I measured my bars- ~24.5" going straight across at the widest point. I can move the shifters, etc. in about another half-inch on each side, which gets me to ~23.5" inches, before they bump into the bend for the riser. That clamping area, where the bar increases from 25.4 to 31.8, is almost 9" wide! And therein lies my problem.

FWIW, the flat bars on my hardtail are only 21" at the widest point, and they feel "normal" to me. Yes, I have tiny shoulders.