My fam has 3 fw trips under out belt. First off, make your res early, you can book 500 days in advance, do it . Next read up on the camping forum on this site. There are many others who know more than I and are willing to help. My feeling if you are driving that far, spend the time there AKA 10 nights Min. This is not going to the park everyday. When I plan, we park everyother day to go two days, take an off day. Our last stay was 14 nights, it was just about right. The last few days, we just hung and relaxed as the parks were at max cap.(xmas-new years week)
halloween and christmas are great times. It will be a 3-4 day drive from CO.
Cost - campsites on way down and back, unless you stay at walmarts or other boondock sites. FW per night $60 off season and $125 prime season(christmas). Site - travel down/back 6 Nights Axp $200 @ FW peak times 10 nights $800 to $1300
Gas - 3100 miles round trip / 9 MPG = 344 gall of gas * $4 = $1377 (somethings wrong when cost more than the room)
Food - I budget $40 per day Fam of 5 - 17 days = $680. Then I throw in a $150 once or twice for character meals. We eat breakfast every day at camper. lunch are brown bag to park or we come back and eat at camper and nap. Then we eat dinner before we head back over for the evening.
This totals axp $3500 w/o RV cost.
RV Rental cost? Not sure on this - May want to see if you can borrow somebodies RV, then learn to use it over the next year or two. Maybe "rent" it from them for a few local trips.
It's a blast, something that rocks. The other option instead of using an RV is to camp in a tent - drive maybe only take 3 days / 2 nghts and or rent an RV in FL. Reducing gas cost and time from CO.
PM if you have any questions