How often to stop on a road trip for a 16 week old puppy?

I don’t feel comfortable boarding my puppy for Christmas, so I’m considering taking him on a 14+ hour drive to bring him with me. He will have just turned 16 weeks old and gotten his final shots within days of the time we would have to leave. The boarding facility/daycare came recommended by a friend, her dog loves it. And she sends him just for fun a few times a month. But since there’s no time for him to try it a day or two prior to being left for a week I don’t want to send him there. I’m worried about how often we’ll have to stop. Will this end up an 18 hour trip? How often will we need to let him out? He holds his bladder ~7 hours at night and has since we got him at 8 weeks old. But during the day it varies on his activity level. He still has accidents in the house, but he’s improving a lot (he’s 13 weeks now). Is it our best bet to drive through the night? I’m hesitant to do that because I’d prefer us well rested. There’s only 2 of us to trade off driving. My puppy naps pretty consistently during the day. So I do think he could sleep for a bunch of the trip during the day.