I use a paid subscription for TomTom on my phone. On the TomTom website I can tell it I put it in RV mode where I have entered my setup deails, length, width and heighth. It will then plan routes using that information. I can then study and tweak the route as needed. Once I am happy it saves the route and the app can synch to my phone.
Couple years ago I did not do this and went on a trip in the Smokey Mountains, the GPS put me on roads I had no business being on towing a TT. Afterwards I discovered the TomTom feature I described above and experimented. For the Smokey Mountains trip I would switch between car and rv and it would change the route. When using the RV settings it avoided the road I should not have taken.