Great! So he finally had a catch up night!
I would also stick to 8 pm bt. I would never do a 12 h day with a 12 h night before anyway... And if you really want to shift his body clock, you have not to go back to earlier bt, in my opinion, until at least the new time is set in.
I have to limit tv time or he just wants to watch it every day all day!
This is F...
Baking with him is a good thing too. Can he entertain himself for half an hour or so? My DS would play with cars for 30 mins alone. Another things he likes to do (he is not much in arts either) is doing these books of exercises for young kids, like finding the right object or shape, or attaching stickers, or copying the word... He is much into numbers and letters, so even if he needs my help to do those I can still do my stuff, like cleaning kitchen after dinner, while having a look on what he is doing.