My son started treatments as an infant. Our doctor typically schedules the youngest children early in the morning, giving them most of the day to recover. By the next morning, aside from the purpera, he has been mostly back to himself. Ideally, I prefer to schedule the treatments on Fridays giving him the weekend to rest. Although, it has not always worked that way and he did have to return to daycare the next day. His caregivers would dutifully apply Aquaphor to his face and give him lots of love. He did not seem to mind getting back to his regular routine.
You will need to take a full day off from work the day of the procedure. For the first few treatments, you may want to wait and see how Day Two goes. One thing that I have been told and am starting to realize is true is that it looks much worse than it feels.
Your doctor will be able to describe how the skin reacts and may have photos that will give you an idea. It is a little shocking to see your child after the procedure, so some advance warning may help you. And again to remember that it looks worse than it is. My son's post op crankiness seems to be due to the anesthesia and hunger, not so much the laser. I have known adults who do not require general anesthesia due to location of their PWS and don't even bother with local anesthesia. It can't be that horrible if someone would voluntarily choose to do that.