Two contradictory thoughts.
i) We use the iSafe car seat travel bags. Big, cheap and reasonably tough.
https://baby-travel.uk.com/collectio...ler-travel-bag If you check them in you can get away with a reasonable amount of bulky things in there too: nappys, steriliser, etc.
It's large enough for the next stage car seats so you'll get plenty of use out of it, and too big for the Pebble: I think you might well get the Bugaboo frame in too. If so I'd pack that all up and use a Babybjorn in the airport - it's useful having your hands free.
ii) I read it that you aren't taking the bassinet, which would be bulky, but if not you don't have a lie-flat-when-out option while you're away, right?
I would considered getting a second pushchair, suitable from birth, mainly for your travels. We have a Chicco Liteway: simple but effective - won't mount the Pebble but does have flat/upright options and we survived 3 weeks in NZ with our 8wk old. (There are more expensive options, like the Babyzen which folds to cabin baggage size and will mount the Pebble.) You'll get plenty of use for a second pushchair over 3+ yrs, and you don't have to worry about the Bugaboo being damaged. iSafe stroller bag again.