Leaviathan said
The way I see it, it's an entry level Viola so if I need a smaller one it's no big deal, I'll eventually sell it and get a smaller one. From what I'm reading the 16.5" shouldn't be an issue

  

Exactly, @Leaviathan That is why bought that inexpensive 16” first. According to the chart, it was the correct size. But some people are able to do more with their “wingspan”. I could not. My muscles are too tight. It wasn’t right away, probably due to really wanting to do it. I had upgraded to a better 16”, before I cried, “UNCLE”. I thought the tightness would losen as the muscles got used to the movements, did not happen. Later I was getting neck, shoulder and back soreness. I traded it in for the 15 1/2” and that is perfect. That little 1/2” difference made a world of difference. My sound with that 1/2” difference did not change, except I did get a warmer viola. I absolutely love it.

There is a big difference with the fullness and strength of the sound between the 15 1/2” viola and my lovely 15” pawnshop rescue viola. The 15” is not nearly as strong, but has a lovely sound, even when the professional violinist/violist at the violon shop I go to played it. She made it sing, but as we all noted, the strength was lacking a little in comparison. She said it was a great little viola. I think better strings will bring it to life. Some day.

Anyway, I digress, as usual.The chart was almost correct for me. Who knows, maybe the issues had to do with my back issues.

I hope the 16 1/2” works for you because the larger the viola, make and quality taken into consideration, the fuller the sound. Maybe, you can try an 18”? LOL Seriously, as a lover of the warm and soulful viola, I am so excited for you.