Anyone have any tips for helping a 5 month old nap longer? My LO has always taken 45 minute naps and I can't for the life of me figure out how to stretch them longer. I've tried in the crib, in the pack n play, with white noise and black out curtains, and everything I can think of.

For the record, he's not upset when he wakes up - it just hits 45 minutes on the mark and then he's rolling over and looking around or playing with his toes and talking until it's time to eat. And he sleeps through the night, so I know he's capable of sleeping through more than one sleep cycle.