I highly recommend the Think Tank Airport Accelerator (without rollers)
It hits cabin luggage size. It's decent but very protective. I travel with it for over 5yrs with
FS7, EVA1, PhaseOne medium format stills cameras, DLRS and I haven't had a single issue at all.
It's not a choice for a 20mi hike but quite comfortable if you have to walk some way but
no trolley available.
Most roller cases weigh >4kg and the airlines get more and more strict with the limit of 8kgs.
if you cannot rely on a media pass.
I use a Think Tank Airport Advantage. Broken down it can take my C200 and a handful of lenses and batteries. I remove all the inner dividers and wrap everything in Domke lens wraps (or equivalents from various manufacturers). It gets somewhat heavy, but it's on rollers and fits in every overhead bin I've ever run into (including some very small regional jets). Laptop goes in the outside pouch and can be removed for the smallest of overheads.