Since I didn't have any 4-5 hour workouts in the pipeline, I did some testing in my car driving from Copenhagen to Stockholm for the Half marathon this weekend.
I tried to simulate a long workout, so I kept the watch on and active even on two occasions, where I was inside buildings.
The results brought shame to my previous assumption: I tracked consecutively for 4:27:27, approximately 20 minutes shorter than what I have previously tracked consecutively. I figured the watch may use more battery when it looses gps-signal, because it scans more?
I didn't have any ANT devices attached for the ride, I don't know if the results would have been different, if I had had that?
All in all, battery life seems to be on the same level as before the updates in mention