We started out many years ago with one of the first iPads. $25 per month for 2gb AT&T, could turn it on when we traveled, turn it off when we did not. Got e-mail, google maps, and internet. Started traveling more in the MH a couple of years ago and needed more. Our new laptop had a built-in ability to connect to 3g4g. But we went with the AT&T, Apple 4s with tethering. Basic single line with 450 minutes, plus unlimited texting and unlimited calling to any other cell phone, which is $20, and 4gb tethering for $45. Additional gb is $10, so not a big deal if needed. On our last trip that was 5 month, we managed to get e mail every day, pay our bills on our own network, and browse the web, never went over our data 4gb limit. We did learn there are limits. Down loaded some Christman music and a few other down loads that did near our limit. Real easy on AT&T to know where your data usage is at any time. Call *3285# and they text you back within a minute with up to date data usage. Of course, always choose free WiFi when available. And one month long stay offered WiFi for $20 for the month. Still used the AT&T to pay bills because I don't feel comfortable doing it on public WiFi.
We were in a couple of Federal parks where there was no WiFi and the Phone internet worked fine. We just bought a TP Link WA5210G to help access WiFi that may be available that could not be picked up by the computer WiFi. We will see how it works. Like to see a thread on the RV WiFi extension,