When my daughter had to have a sleep deprived EEG, my husband and I took shifts. We kept all the lights on, played music and danced, played games, played with some new toys, ate treats, etc. We tried to make it as busy and fun as possible. She was 2 1/2, and I’ll be honest with you, it was very challenging, she was grumpy after getting so little sleep, and it took a couple days to get her back to normal. I would try your best to get someone to come help you.

Or have someone go with you who can sit with him and keep waking him up

Give him some candy on the way 🤣 keeps my kids awake lmao but I don’t know how well it will work when it’s time to sleep for the test lol