Marci - My daughter's first surgeries (at birth, 2 months and 11 months) were before she came to us. And at that time she didn't crawl or walk (she was/is pretty delayed physically), so not the same as your running jumping toddler.
I CAN tell you about the surgeries when she was with us though
. At 3.5 she had the Fontan (supposed to be 3rd and final surgery for HLHS). She did VERY well with this one. Surgery was on Monday, she was extabated before she went to ICU (like ddw said how long they are on the vent is key). She left ICU on Wednesday and we went home from the hospital on Saturday. She did lay around at home a lot and watched a LOT of Nemo! But about 6 weeks later school started and she was ready to attend pre-school on her regular schedule. Plus she never really had run or jumped or played physically alot so for her lying around a lot was more normal.
The surgery she had last fall was a doozey for us (but nothing like DDW and Cameron). She had a Fontan Revision (so obviously the Fontan was not her final surgery and she probly still needs more eventually), they also had to repair a leaky valve that they weren't expecting. She had surgery on Monday but was on the vent for 3 days and in ICU for 5 more days and we were in the hospital 2.5 weeks (plus another 4 days at a Ronald McDonald House close to the hospital). So it was more of a 3 week visit than 5 day visit that time. Her recovery on that one took a LONG time. Her surgery was October 15th and at Thanksgiving she was still recovering. By Christmas things were much better and she was able to return to kindergarten (only 1/2 days instead of full days) after the holidays in January.
BUT my daughters heart condition is very complex and she didn't attend school full days before the surgery (but the last month of school she was able to!). I think your sons recovery time would be much easier and faster because he's a healthier kid to start with. My daughter has pretty much always been "sick" so it's much different.
Please keep posting and we will help you any way we can!
Hugs - Suz