I went solo years ago for the very same issue. My wife was nursing and there was no way she was going to take both kids to ATL and then try to get a trusted caretaker there for a 2 hour dinner. I wouldn't say she missed a whole lot. I left as soon as it was acceptable and didn't do the after party stuff. In training after all. The social aspect is over rated. I have yet to run across any of the managers who attended (good thing IMO) in the years since.
The guys I hung out with are spread to the winds and I occasionally run into them every few years but unless you plan to work the room for an instructor or management job no real benefit. The real work was still ahead and we did our own celebrating later. The dinner was forgettable in my opinion. Maybe 3rd airline does that to you.