I hear you on backups. With the propane fridge though, they are SO inefficient when running on electricity, that 12 volts is almost useless (as a backup source of power). I mean, they take something in the neighborhood of 20-30 amps if I remember correctly

They are just as inefficient on AC power, but if you're plugged in you don't "notice." The DC compressor refrigerators can be had with AC connections as well (it's around $100 extra). Typically that's not extremely needed because if you are plugged in your AC charger is charging so you can run the reefer on DC and it's almost the same thing. But I still got mine with the direct AC option for reasons such as you state. If I have the DC system down for some reason or whatever, I can run the refrigerator directly on AC. I did that just last month at my friend's house actually (for various reasons).
That's not to say everyone should ditch their absorption refrigerator; I'm just discussing options. One "interesting" thing is that if you are equipped to power a compressor refrigerator via solar panels, then it's actually handier than propane in a way. By that I mean that my camping buddy with an absorption refrigerator will have to go get propane, whereas I can just keep "making" my own electricity at the campsite. It's true that one has to get engine fuel and/or dump/fill on a regular basis anyway, but you can do those yourself, whereas sometimes getting propane is a hassle because an "official" person has to do the filling. Then the gas station is open but the propane filler only works 9-5, is sick, is on break, there is a big line, etc. etc. In contrast, now that I only use propane for cooking and heat (and I don't camp in winter up north), my propane tank lasts "forever." That was a side benefit I hadn't really counted on. But of course there is no perfect/one/best solution for most things - so it just depends on each setup/choices/use-case. I primarily boondock, so that's how I'm set up.
Side note on your batteries: I think you are absolutely right not to put in four (which would be around 420 ah, right?). I can't see possibly needing that much, it's a huge amount of weight to carry around, and "extra" battery to buy each time (and they all go bad eventually), and the main thing is the ability to charge back up. If I were doing it again, I might only go for two batteries (250 ah in my case) instead of three, just because I don't think I need to haul around the extra, and that would be 50% of my next battery purchase already in the bank. I'd rather have more panels in ratio, because sure, with huge battery bank you can get through a week of cloudy days, but then you have to put it all back somehow... That said, I'm sure there is a scenario where that would work well (maybe go out for four cloudy days, then plug in at home for a week). But just saying that the hugest battery bank isn't always the best.
On the solar, unless things were changed drastically (and I highly doubt it), don't plan on using the stock wiring or controller. They are way undersized, the controller is poorly located (well, it was on my era - maybe on yours it isn't - on mine it was a good 18' of wire from controller to batteries). That's fine if you want to run fire hose...
I wouldn't even "trust" any manufacturer's suggestion. Not because I think they aren't trustworthy, but rather because it is so easy to calculate the voltage drop for yourself (online calculator). Then you can decide how much power you want to throw away, where you want to locate the controller, what size wire to use, etc. They can throw out reasonable numbers... for their decision on what's reasonable. My ever-mentioned camping buddy had a professionally installed system and it was not sloppy looking or tiny. And yet when we re-did it a couple of years ago, we found legs that had HUGE voltage drop. He was having trouble getting charged back up every day, and his batteries were not lasting very long. We made more than a few changes, but the really big one was eliminated voltage drop. There was lots to get rid of. Now he's back up to 100% every day in the morning, and planning to replace his absorption refrigerator (same one as in the Chinooks) with a similarly sized compressor unit.
If you like, I could run some numbers for you. Not to horn in, but only if you are interested. What I'd need to know is these things:
1) Size of panels (specs not physical size), and length of wire run(s) from panels to controller. Also if you plan to wire in parallel or series parallel.
2) Length of wire run from controller to batteries (or bus bar).
Once you have those figures in hand, then it's a matter of you can have shorter/thinner wires, or longer/fatter wires for the same ultimate specs. If you run the panels in series (i.e. you'd put two in series and then the second two also in series and the two pairs in parallel), then you will double your voltage from panels to controller, which halves the amperage, which halves the voltage drop. In other words, skinner wire over a longer run. (You have to have an MPPT controller to do this effectively.)
Fun to have you on board and doing all kinds of mods
PS: Just read about your pup. Sounds like a great companion, and pup has a great life. Win/win! Keeping a consistent temperature is one of the "advantages" of a compressor refrigerator. I put that in quotes because it's not that an absorption model can't do that. They are just a bit slower to respond to changes (i.e. you put "warm" food in), and they do tend to vary a bit more in my experience. Of course you do have to have the power to run the compressor refrigerator, but it sounds like you will have that. OTOH, one thing at a time, right? (Or should I say "ten things at a time, right? "

I try to keep it under an even dozen

)