Snow tires for a RWD vehicle

Maintenance/Repairs
1

Hi I drive a 2002 Nissan Pathfinder rear wheel drive SUV with 153,000 miles on it. I recently took it to the dealer to diagnose a problem. The car shakes when going around 70 mph and sometimes even around 40 mph, it’s very random. I’ve had the tires and alignment checked and have no issues with them. To fix my issue it will cost around $1200. They said the rear linkage would have to be replaced on the car. . I live in Colorado and due to the age of the car and the fact that it’s a RWD, plus driving up to the mountains in the winter, is it worth it to fix the car and put on snow tires for the winter or look into getting a new carsuv? Thanks for your help.