Just a thought, but why would you rule out a whole half of the country over a time zone or two. Your weather requirements rule out any culture in CST other than Chicago. One time zone over, you've got Denver which fits the bill for everything you listed, and is about the cheapest place to fly from to anywhere else in the nation.
Never mind a whole coast of great places like San Diego, San Francisco, Portland, Seattle...
I'll take 100 in Phoenix or Las Vegas any day over 78 in Orlando. Humidity sucks.