Most RV'ers setup a P.O. box in wherever they are claining as their home state, usually a state with low cost RV registration.
Then most anything important you can setup paperless billing or statements. I get very little mail these days and the mojority of what I still get it junk.
Online banking and paperless statements, paperless billing from anything else, opting out of pre-screened credit offers, etc.

Sign up with two banks, open checking, savings and credit accounts then close the rest. I say two just in case you can't reach one or one wants to charge an atm fee or somehting you can just use the other. close all other credit card accounts so you can simply do all your banking from those two web sites.