From East Glacier, US2 back to Browning and 464 to Babb is best. 49 has a steep sharp climb over a ridge, and 89 to St Marys is curvy and hilly.
89 to 2 and north is the flattest route. 17 to 6 goes to Waterton, which is supposed to be as scenic as Glacier. But the border crossing is smaller and may have limited hours. 6 and 22 run closer to the Rockies front range.
In a car, 541 and 40 is my preferred route to Canmore, since it runs through Kananaskis Country, where the mountain views rival Banff. There's good Provincial camping here. But 40 is the highest paved pass in Alberta, and closed to traffic in early summer.
Last time I drove the area, I stayed in the parks to Jasper, and tooks 16 and 5 into BC.
The main route to BC is Hwy 1 from Lake Louise over Kicking Horse Pass into Yoho. From the east the climb to the pass is minor, but the drop to the west is long. Also I've seen videos of construction work along the highway where it passes through a canyon near Golden.
93 to Radium Hotsprings in a good alternative. Grades are somewhat less and views still good. The final drop to the town, roughly starting the hot springs may be the steepest and narrowest. Pay attention to your brakes.
Hwy 1 through the other Glacier NP is scenic - a major route with good pull offs. When I crossed the other way, we stopped for short hikes about 4 times.
If taking the Radium route, use 93/95 to get to 3. If needed at this point you could easily cross back into the USA and take its route(s) across the Cascades.
3 has its highest pass west of Creston. Beyond that it can feel like a roller coaster, up and down all the way to Hope. A while back I saw an article about a truck mountain driving school based somewhere along this highway.
It was the least damaged of the routes to Vancouver, and I think, at the moment, the only one open to all traffic. Apparently commercial traffic has been taking 5A from Merritt to Princeton to get to 3, and that's been causing traffic problems and accidents.
My favorite part of 3 is where it passes through Manning Prov Park. That has good camping, hiking, and a mountain climb for your toad.
5 Merritt to Hope is just opening to commercial traffic, with many temporary patches. Who knows when that will be open to general traffic. 1 through the Fraser canyon used to be the main route to Vancouver. It too was damaged. They are still working on a couple of major bridge fixes. Check
https://www.flickr.com/photos/tranbc/ for repair work photos.
The first time I crossed BC I took the northern route, though Lillooet and Whistler. Then it was still a gravel logging road, now it's paved, but still high with steep grades. It's open now to essential traffic with winter driving conditions being the main concern.
DriveBC is the main road information site. Keep an eye on conditions there, and don't be afraid to detour into the USA if needed. WA20 has mountain and lake views to rival BC (and gets a lot of discussion here).
