I think I stumbled upon a little sleep trick.
My youngest is 5 months old and went through 2 weeks of waking every 1 1/2 to 2 hours at night and would only go back to sleep after eating. At first I thought that maybe this was a growth spurt, but then I realized that during the day she would go 4 to 4 1/2 hours so it must not have been a growth spurt.
Then it happened.
I remembered (after being back from vacation for 2 weeks) to turn down the thermostat before going to bed. You see, we used to always turn down the thermostat before going to bed but had gotten out of the habit while on vacation and had forgotten since returning home. Well, that first night of me turning down the thermostat, she only woke once. Then, the next night I remembered again, and again, she only woke once.
My guess is that just like me, she was getting too hot during the night and it woke her up (just like it did me). Getting up to eat cooled her down since she was out from the blanket for 10-15 minutes.
This isn't something that I would have even thought would affect a baby and it certainly wasn't a suggestion when I was asking around for advice on what to do for my baby that wouldn't sleep anymore. I figure that maybe it might help someone else who is as perplexed as I was.