I drive between Vail, CO and Denver, CO...and use 8 wheels and 8 tires.
4 'All Season' tires that have great wet, ice, and snow performance for an all seaon. That is what I use for the summer. It can snow or ice over in August on the 11,000 foot passes.
4 top rated studless or studded snow tires for the winter.
In Denver, if he never goes skiing etc. then he needs all season tires with outstanding snow/ ice/ and rain performance. The Goodyear Tripletred , Michelin Hydroedge are worth looking at.
Look at tirerack.com and see what tires in his size get good survey results.