"As I am from East Canada, it is around 5000 miles to the border and back"
I'm in central Maine..maybe 400 miles away from you in Quebec. For me, it is worth the extra distance going to Mexico. Where will you get an ocean front campsite in Florida for less than $100 - if you could even find one.
Florida and Mexico are apples and oranges. For me, it's worth the extra time and money to go to Mexico. I'm still working - not yet retired, so if I can stay 6 weeks in Mexico I'm lucky. Right now a motorcycle is my choice, but once I retire it will be an RV again.