Why not just get a le pliage or a canvas/nylon tote that you can fold up and keep in the bag at all times? It can even double as shoulder carry option if you need to go hands free.Question: who would know whether an LV Keepall Bandoulière 50 could fit a Hermès HAC 40 inside it? Trying to justify a HAC 40 purchase to travel safely with it. Thanks!

I don’t have an H bag but I do always have a foldable shopper with me and I can put my bag in one when travelling and have to put it under the seat.
(For my BV large cabat my bf made me a sleeve in rainproof, ultralight material that I always have in the bag and I can just slip it on before putting it in the overhead bin or if I need to put the bag on the floor somewhere.)