If it were me and was insistent on taking this drive, I would do all the above and buy another set of tires or more likely, simply rent a more suitable, winter ready car.

 

Couls she not wait until summer. 3283 miles each way.

Also, Covid-19 might cause you non-entry thru Canada. You should check this out with the Canadian authories before leaving LA.

 

Unless all of those places she wants to visit are in Canada (which you may be prohibited from visiting anyway at this time), I would look into taking one of the ferry services from Seattle if you really have to have this car up there. We had to cancel our Alaska trip scheduled for last August and September because of this (^&^% virus.