Don't be afraid to use a Sprint or Tmobile based service these days. Both of those networks have seriously stepped up their game the past couple of years. I carry a pre-paid verizon jetpack with the assumption that my Sprint based boost mobile service is going to not work somewhere that the Verizon one will. When we first hit the road this was a real thing, but now it's been over a year since I needed to activate the jetpack. The coverage upgrades are real! I actually found the opposite to be true recently when driving the coast from SF to Santa Cruz. Verizon barely worked at any of the pullouts and was 3g when it did. Meanwhile my boost service was still getting LTE.
My boost mobile plan is 55/month and gives me unlimited, no throttle, LTE data. It also allows me to use the hotspot feature on my phone but that is capped at 8GB. I get around the 8GB cap by using the following app:
https://play.google.com/store/apps/details?id=com.koushikdutta.tether&hl=en - This allows me to use my laptop with the unlimited high speed date from the phone, bypassing the need to use the 8GB hotspot.
I use a moto E phone that I picked up for $50 at best buy, I think it might be even less on Boosts website. No complaints at all, best phone/service experience I have ever had to be honest, and I used to be a big Verizon only guy paying over 100 bucks a month for the service and several hundred bucks for new phones. Never again.