I use and have used nothing but Garmin GPS units for the last 20 ears or so.. I currently run a large screen Garmin Nuvi ( not RV ) GPS.. have traveled all over the western USA with zero issues..
I have loaded in the Low Clearance POI for my unit and never worry about it
https://www.lowclearances.com/
I have also been evaluating this nice App on my iPhone for the last few months and am going to compare it against my Garmin in May when we make one of our annual trips to YNP
https://rvlife.com/app/
So far I like what I see with the iPhone App