I am based at MSN, where I'm on a Delta Connection CR9 most of the time. I purchased the Away Carry-On (not the Bigger Carry-On) for exactly this purpose. It's 1" smaller in each dimension than most rollaboards, but honestly holds the same clothes and shoes just fine. I purchased it without the battery, which opens up more space inside the bag. The battery takes up a lot of space, you have to remove it every time, and honestly there are outlets everywhere now, so a battery is really an outdated feature in my opinion. I've had the Away Carry On and also an Away Everywhere Bag for almost a year and taken them on several trips. They are well-made, hold up well, and attractive. With the Away Carry On in the overhead and the Away Everywhere Bag under the seat, I can carry almost as much as a 25" checked suitcase but carry it onboard. I'm very happy with them and recommend them if you're on CR9's a lot.

Note: There are a few CR9's in SkyWest's fleet that have TINY overhead bins throughout. For that reason, I usually ask the gate agent for a gate-check-tag just in case I get down the jet bridge and find one of those.