Our only experience with a hot spot is with Verizon. We have been Verizon customers for about 20 years but only activated our phones as hot spots about a year ago. During the past year we have traveled through maybe a dozen states and it has always worked great for us.
Would encourage you to take a look at the Mobile Internet Resource Center website (the free part). They provide (supposedly) an unbiased opinion on hardware & data plans for RV folks & boaters.
When I went through the exercise upon going full time (12/2019), I went with AT&T & Verizon as my providers & elected to purchase a Peplink CAT-18 cellular modem/router for the network in my RV. The hardware device provides a lot of flexibility. Finding data plans that allow it to operate at its full potential can be challenging.