Question for Breastfeeding Moms in Guard/Reserve

With my due date fast approaching (I never thought it would go this fast!), I need to start making considerations for breastfeeding while I’m on drilling status. This is a long post, but I’m hoping any advice you can provide will help both myself and anyone else who will soon be in this position!

1)      My  drill schedule ranges anywhere from the normal two-day drills where I can come home at night, to two-and-a-half-week Annual Training in another state. Thankfully, my son will be about a year old before my next Annual Training, but I will have several overnight events while I'm still exclusively breast feeding.
Any tips on:
A) Make sure I’ve pumped and stored enough milk to make sure he’s well-fed while I’m gone?
If I’m still actively breastfeeding, I know I’ll need to pump to at least stay comfortable. Should I just pump and dump, or is it worth the hassle to try to make arrangements to bring a cooler to store any pumped milk?

2)      Were any of you able to get your unit to make accommodations for you while pumping? Say, you’re at drill, and you need to take some time to yourself to take care of pumping. Was your unit receptive to making sure you had a private area, or were you forced to resort to sitting in a bathroom stall? I’m not sure how to approach the subject with my command. Since we are a Headquarters unit in a State building, there are never any empty offices to use, people are constantly coming in and out of the locker rooms, and I feel that just sitting in a stall is a little too unsanitary.