I'm planning an Escalante trip for early-mid May, by packraft with much the same itinerary as yours. Trip planning brings out my inner geek, so I do a lot of research. I realize sh*t happens, but starting off from a baseline of average data makes sense to me. What I found:
-My planned trip is Fence in, out via Crack in the Wall. Comes out to right around 40 river miles.
-A few posters online said 13 miles/day was about right, 15 was a "big day." Look at www.packraft.org
. I want to explore a bit, so I'm going to estimate 10/day, which seems reasonable to me, so 4 paddling days. A day on each end for travel, to/from Denver. Possible I might go faster or slower.
-Note that some online posters were doing a LOT of side canyon exploring, e.g. canyoneering with ropes/harnesses. Not my cup of tea, but I would like to hike a bit to check out some rock towers, etc. So I think 10/day is a good enough estimate. But of course I haven't done it yet, so it's an estimate.
Have fun, be safe,