Currently we have Thanksgiving week 2012 booked (sun-sat). We initially booked that because the kids, ages 9 and 7 at the time of the trip, would miss the least amount of school days...just 2. Plus wife would also only have to take 3 days of vacation. Now am 2nd guessing that trip....worried about the 860 mile trip back with holiday travelers, the fort being packed and of course the parks at capacity. We only plan on 2 days of parks so the plan would be to hit those on Monday and Tues. We had to go up to a full site because we would be worried about empting the pop-up cassette toilet (no open sites during that week.
So what would you do??
Stay with thanksgiving week...least amount of days out of school and off...more full..and bit more $$ (also get dark earlier)
Go in first week of June right after kids are out (we did this in 2010). Not too bad at the fort or parks...just Hot
Go in early Nov. Same price as June, temp better but kids and vacation take a hit.
So what would you do??
Stay with thanksgiving week...least amount of days out of school and off...more full..and bit more $$ (also get dark earlier)
Go in first week of June right after kids are out (we did this in 2010). Not too bad at the fort or parks...just Hot
Go in early Nov. Same price as June, temp better but kids and vacation take a hit.

Live and learn...and we now add an extra day onto any holiday weekend travel. So I'd do the Thanksgiving trip, but I'd keep the kids out that Monday and avoid the traffic if you can. Also, use something like Tour Guide Mike or Touringplans.com to make the most of the heavy attendance days. Well worth the $ when we've traveled during school holidays. The beauty of going to the Fort is the ability to get away from the big crowds and just kick back