I am assuming he won’t be able to go to bed at a decent time. I wake up at 6:30am most days and I know I couldn’t go to bed at 6:30pm. If he woke up at 3pm, it would be a tall order to fall asleep before ~4am I’d figure. Which gives him ~3 hours of sleep.
Not my GPU but my friend’s. He has nothing but good things to say about it. $600 USD which translates to ~£540, but obviously buying it over there the price might be different .