Traveling and extra milk!

Gonna be traveling out of town for a week next month. I currently make double what baby needs. What do I do with the extra? Is there anyway to bring it home safely? Or do I have to pour it out? I was thinking of donating it but don't know how to go about doing that. I have friends with babies where I'm traveling but I have no idea how to approach that subject. I'm afraid some may be weirded out by their baby eating other mom's milk. Thoughts? Advice?