Long ago, the HITR road went all the way to Bluff, UT.
I've looked at topo maps, and it looks like some it still exists from Bluff, to the west.
And of course, you navigated from Escalante to the east.
Portions of the middle are isolated by the resevoir formed by the Colorado River.
HITR is a place I want to return to. Been there once in a soft-core SUV, and could only go about 50 miles before the road began desceding steeply over the sandstone ledges. Late start, we worried about running out of time, and getting back up the ledges if we went down, and went no further.
I want to go back on my motorcycle (more offroad oriented than my g/f's Honda CRV) and explore further. Would love to hike all the way down to the Colorado River, but I don't know for sure if that's ever possible - the photos of the HITR trail that I've seen are decades out of date, and even on foot it may not be doable. But I hope it is...
Doug, my wife has done the hike from the end of Hole-in-the-Rock road down to the lake. She says it's a bit of a scramble, but really not bad.
Some people in my 4-wheel-drive club have driven the portion of Hole-in-the-Rock east of the lake. Apparently it's quite rough, requiring a modified 4WD vehicle- but it's still there!