Sounds like you have a Class A, B, or C (some time of motor home). What about your starter battery on the RV? If you start your engine, it should begin to recharge the 'house' battery via the converter. Or, just to get you going again, are there any neighbors who can give your battery a jump?
A solar panel of about 100W, if you can get decent sun (not too smoky), should keep a typical house battery charged. I'm also wondering whether the generator, once it's running, could power a battery charger (the kind you'd plug into shore power) besides your freezers.
Mike G.
Liberty is meaningless where the right to utter one's thoughts and opinions has ceased to exist. That, of all rights, is the dread of tyrants. --Frederick Douglass
photo: Yosemite Valley view from Taft Point