The real question is…do you need to work for the next 11 years? Look at your current financial and family situation and if possible, take to Full Timing and traveling before you are too old to enjoy it. We have a daughter in Omaha and plan on spending a few months every year visiting her.
We recently retired for military service at 47 years old and we have chosen to be full timers at this point in life. We are living 'comfortably' on 40K/yr and haven't touched (don't plan on touching) our retirement investments. We have been doing it for 12 months so far and we are planning on doing it indefinitely in the RV while we are still young. We've been across the Midwest and are "wintering" in Florida this year (good choice with 80+ degree December days).
Also, depending on your occupation, you might be able to 'go mobile' with your career if you have the right skill set.
As for RV Park prices, if you find a place for $400/month, then you have done well. Most parks are running $500+/month and in peak season can run over $800/month.
Again, it all depends on your "life plan". What do you want to get out of RV living. If you are planning to stay in one place (Colorado), I'd recommend getting an energy efficient apartment for the next 11 years while saving the additional money for the traveling when you do retire.