Denver will likely be chilly, with daytime highs in the 45-55F range much of the time, but late November is definitely winter. Expect at least some snow by the end of the month, and you could definitely have much colder weather, so bring warm clothing.

There are lots of things to do fairly near Denver. Breckinridge is a fairly short drive, and is a very pleasant ski resort town worth a weekend. Rocky Mountain National Park is nice, but you'll have to judge based on weather. It could be sunny and relatively warm, or it could be socked in with snow. You could still visit Estes Park and stay at the Stanley Hotel (from The Shining).

Don't focus on mountain passes; nobody really drives over the passes, anyway, and Eisenhower Tunnel will get you to western Colorado if you want to go.

If you think you'll need snow chains, I'd advise you to just not drive to that area, especially if you've never driven in snowy mountains before. It's a sign that the weather is bad enough it's somewhat dangerous. Cars in Denver will have all-weather tires that are adequate for plowed roads.