It looks like the male was trying to mate with a dead female, since she is still there in the same position this morning. Maybe that's why the male was taking so long to get the job done.

I went out an hour or so later and they were still at it. Or maybe the male is just relaxing for a while

Here's another photo of it on the garage wall.

This is fantastic!
I especially like your subfamily identifier.
Do you plan to do the same for the non-Ichneumoninae subfamilies?