Welcome to IRV2. You will enjoy this site a lot.
Congrats on you "soon-to-be-retirement"!! I am green with envy
The two suggestions I might do if it were me is set up so you can have many of your bills paid automatically -or online if needed.
As far as mail- how about a "Mail Boxes Etc" They will send you your mail to you at what ever address you tell them to. (...you know you will be at a certain campground for a certain period... they will send it there so it is there when you get there-also let campground know it is coming to you)
Good luck and keep us posted on your trip ...