hjeaton65,
We have almost no reliance on snail mail. Basically everything is done online - bank accounts, payments, bills, etc. And it doesn't matter if we are on the road or not.
We hire someone to bring in the snail mail and look for anything special. We have the largest mailbox we could find. The bottom is removed and the mail drops down into a cement block structure which our house person empties once a week. We can reach each other via email or cell but it's rarely necessary. Maybe a friend or family member can help you?
One battery may be a bit light or not depending upon your usage. We could discuss this all year but why don't you go a FHU park, don't plug in and see what happens under your camping setup? I'd run the furnace a bit or not if you're the snowman type.
The Alaskan Camping book by Church has 486 pages of camping information including electric, water, dumps etc. Don't leave home w/o it.