For a weekend trip for which I need to pack a suit, I usually take a garment bag and a backpack (both carryon), and that's it.
My suit, shirts, shoes, socks, and usually some other non-formal clothes are in the garment bag. Everything else (toiletries, a few pieces of clothing, camera, etc.) are in the backpack.
Seems to work pretty well. The garment bag just gets folded in half if it's going in an overhead (and it's not a tight fold, so you don't really get a crease). If the airline has a closet, I may ask if they can hang it in the closet. But usually not a big deal.
I'm watching Jeopardy. The category is worst Madonna songs. "This one from 1987 is terrible".