I get 5 or 6 nights out of Deep Cycle with no humidification . So if you get good deep cycle and a solar panel 25 or 30 watt panel an controller I think you'd be good .
Interlux follow the directions . I have a Starcraft that I painted 30 years ago, still good .Peeled in two small places , probably due to my prep work.
Pick up line in the tank may be collapsing due to that devil ethanol, makes the line go soft.
Had that problems like that in lots of old sleds .
Or vent plugged .
All that you need is a jig saw and a drill.
Use stove bolts for fasteners .
If you have two tanks , use one to make a door 1" larger than the opening on the stove it will have the curve to help with the seal.
Just make sure the tank has been washed and vented for a week or two.
If you have supplemental heath insurance you may be covered for the cost of a battery . I get 7 days on a big deep cycle with no humidification. That's on a 12v system at a high pressure .