I have a giant tote that holds the valuables- my purse, electronics, jewelry, chargers, etc. Even if they HAVE to gate check your roller bag, keep the giant tote with you under your seat.
I always have a few days worth of clothes in my carry-on. Guess how many times my checked bag has been lost? (It's a lot.)
Pack well! I don't use packing cubes because they add weight. Wrap all your shoes in plastic grocery bags (NEVER let the soles touch your clothes- gross!). Keep your clothes capsule-like. Take all the necessities.