Breast Feeding mom I need advice\help

Ok so my boyfriend has a work event that is next month and it's a weekend in a super nice lodge! I am beyond excited to go have some alone time with my man but am so nervous about leaving my son for the first time this long! I have some breast milk pumped from the beguinning than I stopped pumping... so I'm gonna need a lot of milk I'm sure for 2 days almost 3 away from him! He will be 8 months when we go. Any advice how to build my stash up in time? I do not wanna give him formula. How much does your little one drink of you pump and bottle feed I have no idea how much he is drinking at a time because I have always just had him eat from the breast! 🙄🙄🙄 please don't ignore this if you have any advice please please I'm working so much! Thanks!