Anything under 30 HP is too small IMHO. I currently have a JD 4300 with a 72" MMM, and in heavy grass, it boggs a little. I can't imagine how helpless a 23 HP tractor would be.
I am awaiting a new 3520 turbo (37hp) that should be in soon.
I would wait and try to find a 4300, 4310 4400, 4410...