Fly into Jackson, WY - end in Jasper, AB
Riding north, you generally have the sun behind you.
Plus there is a net elevation loss of about 4000 feet.
(Of course, with all the climbing and descending, it seems like a wash.)

It take a week+ to get from Jackson to Glacier NP.
Then a week+ to get from Glacier NP to Jasper.
That's a fairly leisurely pace with days off.
My guess is 14 riding days total - thus 7 off for exploring.
(1000 miles - 70 per riding day)

I took 19 days back in 2005 -
Including riding out and back on Going to the Sun, hiking, and days off.
https://www.crazyguyonabike.com/doc/..._id=26427&v=O5