Just as we were about to leave on our big (half) lap I thought I'd store some jumpers and other warm clothes. I bought a few vacuum bags, got back to the van and realised I didn't have a vacuum cleaner! Doh!! This video shows how I fixed my problem: https://youtu.be/vwFc6qn_xoQ
Ah, that would work. We us zip lock bags to put meat and other food in before freezing it. To get the air out we the bag up or sometimes put the bag under water. This is similar to your idea as the air is pushed out rather than sucking it out.