@moon_under_water I always have a mobile phone that I check it with, but on Amtrak, which I travel very frequently (hate flying) I have to tell you I’ve had long drawn out blank spots where there was no signal. Sometimes in the middle of nowhere cornfield land, there’s just nothing. You won’t be using a phone you say, however, this device you linked to says “Services good within the United States only and where the Sprint network is available.” so it uses the sprint network. ” So it uses the same cell towers.
I had the worst time finding a connection with sprint. Once went 200 miles without getting one, but that was a long time ago. I switched from sprint because at the time, I was constantly being reamed for roaming charges. I’m sure they have more coverage now, and perhaps better plans involving roaming, than they did years ago. That was a long time ago. Still, I would check the coverage area of Sprint currently, compare it to your travel area, and also inquire about “roaming” just to be certain.