We dry camp around 40 nights a year, have 648 watts of solar and 4 trojan t125s wet cells. That gives us 250 amps usable power, that is if you want your wt cells to last. they are designed for full draw down, but then you'll get around 3 years out of them. I sold my first TT after 10 years and they were still going strong. All you need is either a volt meter plugged into the 12 volt house system, or check them manually. I would love lithium but prices haven't come down enough for me. As stated a back up gen is a good idea. Since we solar-ed we no longer carry the 3000i, but rather the 2000i. We seem to use it maybe 2x a year as we also work while camping.
While im a solar fan, I am wondering what the cost would be for a propane rv fridge vs cost of solar & batt set up.Just a thought. We seem fine with up to 4 people for a week in terms of food storage typically without a cooler outside.
Good Luck and happy trails!