I did take the cut section of 4" PVC pipe with me on a recent trip. It has holes in it as it is meant for drainage outside at ends of underground systems like the ones I installed at my own home. I was able to pack my wine from EU into it and put some newspaper around the bottle too. All this went in my bag and it was fine. And cost free!
(well in my case it was scrap but pipe sections like this can be found at home depot)