A.C.
I had to make a one night business trip when my daughter was 4 months old. Oh, it was awful. I am a single M. and she stayed with a very good friend. I won't lie...I cried when I left her, I cried when I was pumping my milk, I cried when I had to argue with the TSA about bringing my pumped milk back through (I did win that one), I cried myself to sleep that night.
BUT...they are staying with their Dad, you can be a better M. when you have your sanity, and I believe it does kids good to have some serious one on one time with another caregiver.
I've had to travel a lot in the three years of my daughter's life and there were trips when I just didn't think I could handle it anymore. But, then she got a little older and was experiencing things that I never would have exposed her to...she's been to memorial services, museum openings, and interacts with all ages of children.
Don't make yourself feel guilty for taking a break. Not everyone is "supermom" and it is okay to say you want a little time with your peers.