So it looks like my optimal situation is having an extra seder, a day early, Sunday night. Then my dad can spend Pesach with us and still go to radiation on Monday.
Then, we'll have another seder Monday night sans Daddy, and then my mom and sister might go up to Atlanta and spend the 2nd/3rd night there on their way to UNC Chapel HIll (for Deb to visit).
Matthew and Kalina aren't coming this year, but I think I'm going up to visit them in Baltimore after finals.
They'll be down soon after though, on June 1st, because MY LITTLE SISTER IS GRADUATING FROM HIGH SCHOOL. She's such a grown up.
Maybe more in a little while. I feel like writing today.