It's been touch and go here the last week too. There's two chemo "cocktails" that alternate. Cisplatin is what we call "the bad stuff" where the nurse suits up and uses double gloves just to handle the IV bag. The other is Gemzar, which isn't too bad. She is in getting the Gemzar today, so she should be okay by Saturday. (That's when we start heading south) I can say for certain if she was in getting Cisplatin today, the trip would be cancelled. While we're in Moab, it's "skip week" for the chemo, and that worked out really nice.
All I can say is if someone in your family gets cancer, making plans for anything becomes real iffy at best.