Jefferson Notch is passable!!
I drove the full length of Jefferson Notch Road on Saturday afternoon, June 4th from Base Rd to Valley Rd, the roadbed is passable for cars/trucks, however it looks like the NH DOT is still working on the orad on the Valley Rd. end (it was washed out quite severely with the spring rains/runnoff).
My guess is you can count on this road being passable on weekends, but during the workweek you may encounter road crews on the Jefferson side.
The drive from Base Rd. to the Caps Ridge parking area seems to be stable and other than a couple or precariously leaning trees (you'll see them!), should be accessible during the week as well.
In any case, it looks like repairs on the Jefferson side of the Notch are nearing completion.