Looks like we're getting some interest.
Now for some more details: That part of Canyonlands is considered wilderness, except for the jeep road, and access is very limited. You have to pack out all trash, and carry and use something for human waste as well. It is also a rough, remote road with no amenities or cell service and the tow service charges $2000 just to show up... Campsites and permits are limited to 3 vehicles and nine people, except for Flint Seep, which is 5 and 15. So, we'll likely need a volunteer "trip leader" besides me to apply for a permit so that we can split into two groups if there are too many folks for one site. There are 3 sites at the Dollhouse, all nice, and two at the Maze Overlook, and the others (single sites) are close enough to be able to meet up for the day. We're planning on some part days not riding but looking around and hiking, like to Lou's Spring, the Harvest Scene pictographs and Spanish Bottom, and most notably the 4 mile walk from the Dollhouse out to the confluence of the Green and Colorado Rivers. The country is too complicated and beautiful just to ride around in a cloud of dust every single day...
I'm planning on carrying 37 gallons of gas and at least 250-275 miles off-road - the end of the road at Milliard is said to be around 80 miles from the nearest gas, at Hite. 10 gallons of water besides, more if it's hot. Not good having a serious breakdown out there - not much traffic.
That all being said, if folks want to meet up along the way, our schedule will be pretty much fixed by campsite reservations so we should be easy to find. The Dollhouse is the biggest set of sites and at the end of the most challenging (fun) road there. That place could conceivably hold 27 people and 9 vehicles. It also is the first to fill up when reservations become available to select. In the next week or so, we'll need to get serious about who is actually going to come in order to reserve the campsites in a doable order. I was thinking first stop at the Dollhouse, me spending two days/three nights there in order for folks to arrive (straggle in) and see it. Seems like a good place to gather, since there is so much to do there compared to some of the other places.
Then, moving around to the middle level (it's a maze) for the rest of the trip and out to Hite. Coming in at the upper level to start the trip (past the ranger station at Hans Flat) would mean a fun drive down the cliff face on the Flint Trail might be fun. It is way better going down than up that one.
I'll plan on securing two permits (6 jeeps) and we'll figure the rest out based on numbers. Any questions, ask away!
I'd like to be home by the third week in May is my main time constraint. Went to the Hidden Splendor for a couple days as well - but I like a little more remote... 
The end of the Dollhouse road has a campsite - way above the River but there is a trail down to Spanish Bottom. Beautiful hidden place, about 55 miles from the nearest pavement on its side of the River.
