My girl slept a lot at that age and sleeps great still now at 5 months
I would wake personally because you don’t want him to dehydrate especially with this warmer weather x
Has he woke up through night for a feed at all? Or did you have to wake him up for a feed?x
They're supposed to sleep around 16 hours a day with night sleep and naps throughout the day so little one been asleep 14ish hours by now so I. Would wake so that they can get much needed naps through the day and have opportunity to drink plenty of milk. Maybe speak to your health visitor :) x