What are you running while parked? Are you running your fridge on 12v? Do you use an inverter to run it on 120v? Is the water heater running on propane or electrical? Are you using the heater? Microwave?
All those things can run down a battery quickly. Without a generator, multiple battery bank, solar, etc. you won't be able to maintain a battery for long.
If you are going basic (fridge on propane, water heater on propane, no heater, minimal electronics, etc.), then a better battery can get you through several days at least. I have a group 31 AGM and it can take me through 4 days without a dent.