I get major issues with altitude sickness just thinking about Denver. Sorry - no can do. Not even Tahoe, darn it.
Vegas on the other hand. I would bet that my mom's house there would still be available and, depending on how many of us there were, we could have a girl's party for sure there. 3 bedroom house with 3 bathrooms and a huge living room, completely furnished but rarely used now that my mom's elderly and hardly goes there from So. Cal.
But I doubt many of us would want to go there in July. Unless we weren't going to leave the house. No pool sad to say.
Patricia