You might want to control his water intake and do it the same way you do the food. Put the water down and take him potty after he drinks. The scheduled water will mean scheduled pee and will make it easier on you.

Also, rough play sessions cause them to have to potty. So remember to take him out if he is playing hard.

During the day, you could keep him on a leash near you at all times (especially these first few days).