This year I think I'm going to try Telus. They offer 10gb data and unlimited calling and texting in Canada and in the USA for $145 a month. The only drawback is that you have to lock into a 2 year plan. But it will be hassle free.
We've tried the Verizon hotspot data plan which works very good but has a 2 year contract which you can put on vacation for 6 months only when you're not down south. This turns your 2 year plan into a 4 year plan.
Last winter I tried Straighttalk. Was not impressed. Speeds very slow and during the month of January when all the RVers where in Quartzsite it just plain sucked. A waste of $50 for the hotspot.