Manual chains are the way to go. Simple and easy to fix if ever needed. We have a full size 4wd truck and carry a set of heavy chains from October to April. As the truck has 20" tires, there was a lot of sticker shock when I purchased the chains.

As we sometimes pull a friends enclosed snowmobile trailer in winter, the trailer also has a set of chains. Learned the hard way a few years ago while slowly descending down a mountain pass. Even though the trailer has electric brakes, it jackknifed around and just about pulled us off the road.

Also this year, .gov is enforcing over almost all mountain pass roads, the minimum acceptable tire rating is M&S or those tires with the snowflake designation.

Hopefully this enforcement helps to keep the mountain pass roads open more, as many times the roads get closed due to cars and commercial trucks as they do not have the proper tires and or chains.

Discovery Channel Canada has very good series that depicts a heavy rescue towing company and it employees who attend to many snow related highway closures and vehicle recoveries in British Columbia and Alberta Canada.
Highway Thru Hell