I went from a large room like your old one to a 13.5’ x 22’ room. I ended up with Open baffles, reason is they can be placed close to the side walls due to their dispersion pattern and have less interaction with the side wall. I have mine, Tri-Art Audio Open 5 that are quite large, 5’ from the front wall (front of the baffle) and about 10” from the side walls with excellent results. Definitely have a look at OB’s or similar speakers for long narrow rooms.
Another option is a speaker like the AudioNote’s AN line they are designed to be placed into the corners. Also sounds very nice.