generator on my 02 Fleetwood gets it's juice from the coach battery . . . . I think.
Many Class A's have a push switch on the dash connecting coach and chassis batteries together. That jump started mine for a month while I shopped around for a new chassis battery.
If you're going to be wheels up for month+ you might invest in a battery tender. Make sure what you get says it will MAINTAIN a battery. It doesn't have to be big to maintain. Battery Tender is a brand that made these pretty popular.
I'm not sure FLOAT and MAINTAIN are the same thing.
Best,
- bob