Check for any signs of dehydration: When he crys, does he make tears or are his eyes dry? Is he drinking normally? If you gently pinch the skin on the back of his hand, does it tent-ie. stay in a pinched peak when you release it-or does the skin return to normal immediatly? Is he running a temperature? Is he fussy?
When my daughter was about 2 months old, she would go to bed at 8 pm and sometimes wake up at 7 am with a dry diaper, nurse, still be dry, go back to sleep and wake up at 10 am finally wet. She wasn't showing any signs of being dehydrated, but I took her into the pediatrician anyway. Her doctor confirmed that she was perfectly fine, not dehydrated, and that babies sometimes do that. However, she also praised me for coming in, just in case, even after knowing and checking her myself for the signs of dehydration, since it had been more than 12 hours.
As long as he's not showing any signs of dehydration and is drinking, he should be fine. If he goes more than 12 hours without a wet diaper, stops drinking, runs a temperature, gets fussy, stops making tears or does anything unusual, call your doctor. Otherwise, enjoy the brief break! Good luck!