Most of my enjoyment actually lies in anticipation. Which is to say, about 90% of my fun/stress relief/happiness from any vacation comes from looking forward to it, so I'll offer the suggestion to let your wife know this is coming, and solicit her input (not to say you shouldn't still do the organizing legwork!).
I live in Colorado. It's awesome, and I love the mountains in winter, but weather is not predictable this far in advance...you could have a romantic weekend with beautiful views, or find yourself dealing with a serious storm. For a quick weekend getaway, it might make sense to plan for a warm destination. That being said, it's easy enough to plan to stay down in Denver, Longmont, Boulder, etc., and then take a day trip up to Rocky Mountain National Park (about an hour's drive from any of those, very scenic, tons of mountains). Salt Lake City would offer similar day trip options, for that matter.