I was very impressed by a dignified elderly passenger on my recent trip on Eurostar. This would not work for travelling by air, but was perfect for the train. She had a very small hard shell cabin case - I would guess about half the size of the old standard cabin case.
It had four wheels rather than two and I notice this is the latest modification - I shall be updating my travel cases soon - and was a very pretty colour.
Then she had a tote bag with (I'm guessing) things needed on the voyage and a slender cross-body bag with (again, I'm guessing) the essentials: passport, tickets, phone, cards/money. It all looked very manageable, nothing too heavy, and sorted into priorities.