Big rooms need power. My 300b is working in it’s comfort zone driving my Forte in a 13 X 15 X 8 room It will fall apart if I play it loud.
My 40 w Quicksilver amps are a much better match if I were to listen loud but I don’t.
Unlikely that any flea powered amp can give good results in that size room. Stick with your Rogue for now , get a feel for the Cornwallis , then try a few quality , moderate to higher powered tube amps. So important to try your next amp with your speakers. Would be a shame to sell a good amp like the Rogue and make a lateral move.