If it helps CF, my DH & I just had our first night away from my Blake (we were belly buddies if you remember) to go to a wedding about 2 1/2 hrs away from home last night. My PIL came up and stayed at our place with DS. I was a little concerned how Blake would go as lately he's been waking 2hrly and was only feeding back to sleep and wasn't keen on anyone but me putting him back to sleep. But he was fine, I left a few bottles of EBM for him and he only just used the last one up for his morning sleep about 1/2 hr before we got home. (He was still asleep when we got back). I ended up expressing a couple of times in the car (once on the way up, once after the ceremony which was on the brides parent's farm where the reception was also) and in our motel room after getting back that night and again this morning before we left.

So I guess my recommendation is - find your pump, maybe have a couple of bottles of EBM for the grandparents and your Blake, and enjoy yourself. Given it's 2 nights maybe a practice night would be useful. (oh and definitely recommend Maz's Bpads)