Funny, we head to Cuse that same day the 7th. Neither place should be hard to find things to get into. Denver, downtown area is the most popular, (LoDo area), around Coors field. Rockies are away that day (@Cincinnati), but a ton of really nice rooftop bars/restaurants down there.
Vail has more to do in the summer than in winter, which surprises most people. There's 8 PGA rated golf courses in the immediate area. Very good restaurants that have summer discounts most of the time. That wedding doesn't happen to be at Piney lake does it? There are a lot of mountain dirt roads that go way into all the surrounding mountains, as far as you want to go. Vail village is really fun at night. Let me know if you have any specifics.