Did that on my S-III and does it on my S-V as well.
The only caution I have for you is this..
When I set up a route.. works great,, but if I am in a no-coverage area and do something else, attempt to edit the route, even update the route.... I loose the map, route and all, all gone, no on-board storage unless I specifically request it and then only if the trip is short enough to store.
That's why I use a different system for the motor home.. When doing an 800 mile "hike" the phone is going to give me problems.. The Laptop with on-board maps will not.