Some observations - For the past 9 years I travel from Ontario Canada to the US south-west (AZ, principally). . . .
AS is 32-ft 1987 Excella which weighs over 8,000 lbs loaded with all tanks full. This was checked last winter in Tucson with https://www.escapees.com/knowledge/smartweigh
TV is 1999 Ram 2500HD 1st gen 24-valve Cummins, long bed with cap & club cab. At 55mph on flat land I clocked 16.9 mpg. It only has a 4-speed tranny, so I drop it into 3rd when going through hill country.
I use Verizon cell service, and have the Nationwide (unlimited) + Canada/Mexico (1,000 minutes) plan. Not cheap, but it also includes 10 gigs data per month (in the US only). For internet access while I travel in Canada I have a Rogers "stick".
No issues with my Canadian credit cards when buying fuel - sometimes they want me to prepay, which is OK. Once I was asked to provide the fuel station with my driver's license and credit card - that exception was caused by the fact that the day before some scumbag handed the attendant a credit card and fueled his tractor with 300 gallons and drove off (the credit card was invalid).
I don't plan much ahead, and I'll overnight in rest areas, Flying J's, Walmarts, etc. I'm equipped for boondocking, so I prefer BLM or similar places. I do have a share in an Escapee co-op in AZ and my own lot with hookups.
Having experienced tire failure (GYM's), I have a genset and compressor in the back of the TV. I also upgraded my running gear to include 16" Michelin LTX tires.
The only plans that are "cast in stone" are the dates of entry into the USA or Canada (as the case may be), as these are established with my health insurer. There is only one other "date" that doesn't waver - my appointment at JC for service to the AS going down for the winter or coming back for the spring. All other plans are "loosy-goosy".
And next Friday I hitch up and head south!