CRJ's have teeny tiny overhead bins. If you don't want to pay checked bags fees, I would just use a standard 22" in rolling bag, which will be checked plane side. Even if you were traveling on an A380 don't bank on being able to lay a suit bag flat in an overhead bin in economy. FA's will squish and cram every available space out of an overhead bin.

Place the suit inside the bag while still in the plastic dry cleaning bag. Don't over stuff the suitcase. Gingerly fold in thirds. When you reach the hotel in the evening, immediately remove and if needed hang in the bathroom and run a steamy shower.

If you must go straight from plane to interview without a stop at a hotel for a shower then neatly fold the pants encased in dry clean bag in a small carry bag and carry/wear your suit coat. Hopefully you can lay the coat flat on top, worst case scenario you can lay it across your lap.