I think this is a hard question to ask on a forum. You will know if the horse is able to handle you when you ride it. Just trust your gut and instincts and don't try to force anything. Also if you feel a horse is too small for you when you are standing next to it, then chances are you will feel the same when you are on it.
I fluctuate between 190 and 220 at 5'2" and my 'pony' is a 14hh Arab / pony of America cross, and she had no issues carrying me for 7 years, and I'm not talking about an hour ride in a riding ring, I'm talking about hours out on trails (in the mountains, fields, hill country, etc.) at a time sometimes twice a day. She is now retired to pasture on my parents farm because hubby and I are military and can't take her with, otherwise we'd still be riding no problem.
So I really feel like this is a thing that can't be accurately discussed online, because you'll get a range of opinions and even a few harsh comments. I know if I asked if I could ride an Arab/POA cross that stood at 14hh at my current weight of 220lbs I'd be told no by 98% of the people who responded; and even now if asked for an opinion I'd probably get told I was killing my horse. But time tells and my pony never showed strain, pain, discomfort, nothing. In fact she would perk up and be excited to hit the trails with me on her and we had tons of fun at all speeds in all terrain and even over natural jumps.