I concur for older people, you really need a 10" tablet
(kind of hoping that Amazon come out with a Fire 12 or 13).
I would not pay extra for built in cellular capability. Either use your existing phone for a hot spot
OR, better yet, put the money into buying a cell phone to wifi adapter/router that has external antennas. You can use smaller antennas inside the vehicle or larger ones outside the vehicle when parked.
Many to choose from. Some, like the WiFiRanger mount the router inside and external housing, so do not. You will have to spend some time looking at various models.
This
4G LTE Router WiFi mounts inside. The two "paddle" antennas can be replaced with cables going to external antennas for better long distance reception.