I am an Android user/die-hard fan since version 1.6 (circa 2009 I think) and can't recommend it highly enough for everyday use. I have owned nearly every pure android phone worth having, and at least 3 high-end android tablets. I also have fair experience with the cheaper android tablets like the ASUS and Micro-Center 7" specials, and they work really well for mom/dad/MIL duty AKA light usage.
However, for this specific application I feel that the iPad is the better choice if you can afford to spend the money. The main reason is that the hardware is rugged, super-reliable and much better integrated with its OS than nearly every Android tablet I can think of out there. Every iPad gets updated to the latest OS (except the original iPad so far), android tablets don't. This is fine for a phone that gets used everyday because it typically gets replaced after 2-3 years. But for a remote location navigation device that gets used infrequently and on which your life may very well depend, an apple device is simply a better value. From first-hand observation, the average iPad will continue working better after 6+ years than even a high-end android tablet. You do the math on the life-cycle costs....
Many people seem to prefer the iPad mini because of size, but I chose the Air2 (now its called just the iPad, I think) because it has a faster processor, and a bigger screen is always a boon and rarely a liability (esp inside a vehicle). The cellular model that comes with inbuilt GPS and highest available storage is really the way to go, though it is more expensive. The last thing you want is lack of space for maps at the highest available resolution, and maps CAN fill up 128GB if you really want everything for a particular region. When I go overseas it is one extra SIM card to buy but it really is worth it for a seamless user experience. My typical nav/tracking setup is as follows, YMMV:
cellular iPad with google maps navigation for on-road nav. Screen off for best battery life - maps will still speak turn-by-turn directions.
pair with delorme inreach and switch to gaia gps in airplane mode when outside cell range (saves a ton of battery life).
android phone for backup using gaia or delorme software
torque pro and all other android-exclusive apps (there aren't many) running on phone if necessary.