PLAN IT FOR SUMMER!!!!
We had the worse case scenario. DH is a teacher, I'm a nurse and at that time was working a job that was very difficult to take off from--there simply wasn't anyone to replace me during the day.
Our oldest dd's best friend got the chickenpox sometime in the middle of July, so we exposed both kids.
DD#1 came down with them first. Right around the beginning of August. School starts here the second week of August, dh had to be back a couple of days before that. DD#1 gets the pox BAD, and to boot, several of her lesions become infected. To the point that they were HUGE. I'm talking, the pox part was the size of a nickle and pus-filled, and the red area around them was several inches in diameter. Awesome. So we went to the doc and got an abx. Then she had a reaction to the abx. So we used a different one, after that reaction cleared up. She did not have completely crusted over lesions for 2 entire weeks. So for 2 weeks she couldn't hang with anyone who hadn't had the pox, and she missed the first full week of school.
Four days after dd#1 went back to school, dd #2 came down with them! Could they get them at the same time? Hell no, apparently. While she did not get any infected pox, she was out of school for two entire weeks.
This meant that for THREE FULL FREAKIN WEEKS DH and I had to juggle our schedules. I was working 3-4 days a week, and I missed at least one day of work a week, he missed at least two (at the very beginning of the school year. Oh, yeah, he teaches German and Spanish--try finding a sub that can teach both languages. Didn't happen). My mom took a couple of days off and came up to stay with them to help out. It truly sucked. I had no sick leave, so we just had to eat the days that I didn't work.
I guess my point is---don't plan on the kids getting it at the same time, and accommodate your schedules to plan for the worst- with each kid getting it successively, and being out of school for two full weeks. That is typically the longest--lots of kids are out for a week or 10 days. As luck would have it, both my kids didn't have all their lesions crust over for two full weeks, which is when they are allowed back into day care/school.