Vacation and losing milk supply

Hello all! Need advice or suggestions on possibly losing my milk supply. My daughter will be 4 months when my husband and I will be going on a vacation for a week. (We planed trip before we found out we were pregnant, non-refundable) She unfortunately can not go. I would like to not lose my milk supply. I have been breastfeeding and also pumping to build supply and stash. I do not believe I will be able to keep or store any milk if I pump (so I might be dumping milk) suggestions to keep supply up?