Maps will help you a lot.
Hi Karen, Do you have any good detailed maps of the areas you'd like to roadtrip? If you can't get any locally, maybe your daughter can get them and send them to you, or you could get a Rand McNally road atlas from the RTA store via the link below. If your daughter is a member of CAA, she will be able to get maps of all the US States as well as the Canadian provinces for free. The road atlas has all those as well. Those maps have an incredible amount of information on them, including historical and natural attractions, all cities and towns, no matter how small. Much more than you will ever be able to see within the confines of a computer monitor, let alone a little gps screen. The roads are all shown graded from high speed interstates to historic byways and backroads. Scenic routes are highlighted. Maps will be invaluable during the planning process, and essential when on the road.
You do not say in which State you live, but if you are a member of RACV, NRMA etc. take your membership with you. It will give you access to tourism information from the CAA and AAA all over North America. No doubt your daughter will have trips planned to the local attractions and the stunning national parks of Canada.
I would highly recommend that you drive the Sea to Sky highway from Cache Creek to Vancouver. The routes from Jasper or Lake Louise/Banff to Kamloops and then Cache Creek are incredibly scenic. Make sure you leave enough time to stop at the stunning views and sites. About half way between the lovely little towns of Lillooet and Whistler is Joffre Lakes Provincial Recreation Area, with a great hike to three glacier lakes, one above the other. Probably the most accessible glacier lakes in BC. Absolutely spectacular.
You're in for a great trip, but I will leave it up to you to see all the attractions on the maps and having done your research, decide which places to explore. Glacier NP and Yellowstone NP are two more places which will have limited access and services, being still in winter mode.
Lifey