Help! Building up a stash

Looking for advice! I had to supplement with formula shortly after baby was born due to weight loss and not enough wet or dirty diapers. I have been working HARD to build up my supply and tomorrow will be 1 full week of exclusively breastfeeding for me and baby girl (so proud! I never was able to achieve this with my son). Anyways, hubby and I have a Valentine's day dinner planned for a week and a half from now, and then we have a wedding out of town where we will be leaving baby with my mom overnight. My question is how the heck and I going to build up a stash to feed her while I'm gone?! Currently I am pumping a few times a day and using a haakaa to supplement with breastmilk at night since my supply is still pretty low at night and that is when she cluster feeds. Some days I barely have enough to satisfy her. Idk how I'm going to be able to produce enough to save! Any advice? I am chugging water and Gatorade, taking a bunch of lactation supplements and drinking lactation tea. Help!