I would just like to post that I contacted the Chicken Pox when I was 14 weeks pregnant w/my DS. The vaccine available now was not out yet, and Murphy's Law...had not gotten them my whole life, then at 32 and PG..HELLO! I was immediately given an injection,, varicella something, a triple injection in the behind that knocked me on that same behind for 5 days. I was in and out of it, scared to death of losing the baby, what might be happening TO the baby, was he going thru the pox like I was...the main objective was to keep my fever low so as to not hurt him.
I was exposed by my nephew...my SIL who knew I was pg and had never had them, THOUGHT he was safe since it was day 20 and he did not show signs. We were at my FIL's birthday which is a MUST..no one can skip it.

Well....day 21 my nephew broke out, I had been exposed the day before.
My son wa born healthy enough, but has suffered horrible allergies and skin rashes his whole life. While we will never know if he actually had the pox ( blood test shows borderline immunities, so he has been vaccinated) I can tell you that MY immunuties were wiped out by the injection while pregnant. So, I had the pox, had the injection to save DS, and then I had to get the vaccine to cover me in the future. It was sheer he** to go thru, I don't think I could knowingly take a trip while this was on my mind. I guess you could look at it as if you were one of the exposed on the trip and had no idea, but you do have an idea. I hope the trip is CP free, and if I felt I had to still goI would have rented the car for the entire trip and not flown at all. I know it is a tough choice to make, but from the info you have posted, looks like you can't be shocked if the pox arrive. If your DH does get them, I hope he has a less intense case than I did. They are horrible in adults.
Pam