I think a residential refer is a GREAT idea, now that there are decent solar panels available. So, that is where I would start FIRST, adding enough extra solar to accommodate the extra demands of residential.
Then, I'd fill both the freezer, and refer, with jugs of water up to the point where the remaining space is more then you normally use.
So, with the solar, and water, the night-time electric usage should be fairly low, provided the internal temps of the RV are reasonable.
Then, if not already, I'd replace EVERY single lite bulb with an LED equivalent to further reduce night-time loads.
I'll follow my own advice above, and put a Kill-a-Watt on my own over the next few days.
Bottom line, I really do think that a significant solar set-up, unless you expect to run the genset 24/7 for A/C, is the first step over adding extra batteries. Adding extra batteries is the third thing I would look at doing; and realistically, doing all three (Solar,LEDs,Batts) at once is the best approach.