Ran into a very annoying bug at a place called Gloomreach cavern - at two points in the cavern, my follower seemed to freeze in place, unable to follow me. I actually had to push her where I wanted her to go with several applications of the Unrelenting Force shout. One of the places was a winding road that went downhill along a drop - a road that doubled back on itself as it went down with tight turns. My follower would just stand there, at the top of this winding way. The other place was a drop, where you had to jump off to get to the exit - she just wouldn't, but would just stand on the ledge.

I got past both points by using the Unrelenting Force on her. Really annoying. Took me probably 15 minutes to get past those places, with my companion in tow.

Is this a one-off, or am I to expect other such places in Skyrim?

all you have to do is carry on going and your follower will eventually catch up with you.
I think you wasted 15 minutes.

There is only one cave, and I think that was patched out, where you are certain to get a follower stuck.

However, followers will sometimes just stand there and not move for a while. They will eventually get unstuck. If you want to speed the process along, then just wait an hour and they will be next to you. Note, it is rarely possible to lose your follower in a cave because they fell into the void. If leaving the cell does not bring them back, then load a save from before you lost them. It will take less time than the recovery attempts which are not always successful.

Tried that. Left the cave, walked away for quite a long time, waited, no follower. Went back, and there she was, standing around where I left her.

It's on very few locations where this happens. That I can remember the tower where you have to investigate the murders of the redguard family (forgot the name), there is a place where you have to jump down into a chaurus nest, just before the place where the guy's remains are where the follower won't jump down, unless you push the follower. Yngol's Barrow is another place where you can't enter with a follower. The screen will go black.

I have been through Yngol barrow more than 10 times and I took a follower every time. they were perfectly fine in there.

The point being made, here is that a follower should follow, not catch up with you after you go a distance alone, needing/wanting that follower's help.

I am not satisfied with a follower who freezes, then "catches up" later. That defeats the purpose.

I have experienced this same problem. When my follower(s) freeze, I sprint into them, knocking them off balance. It seems to reset them, and break them out of the freeze. Most of the time, though I just have to deal with it, or save/reload and see if that snaps them out of it.