I enjoyed your report, and have lived through the "I want momma" and sleepless nights to make sure the kids stay warm. Our Momma would NOT be happy if I brought them home with a cold. Have you thought about putting one sleeping bag upside down to keep them completely contained?? Seriously, I agree that it's best to have a thick base layer since kids wiggle so much.
It is worth the effort, and they will cherish these photos & memories all their life. Besides...Momma probably appreciates a break with only one kid!!