I think a shorty splash/drytop with swim trunks is warm enough..Of course it was 73 deg also and I'm cold natured.
We did the upper on saturday and it was a blast. 20 stitches seemed different to me this yr. It had more drops(middle line) in it from what I remember. Steve (russellfork) may can add some comments on it..I saw him at the bottom of 20 stitches and he also mentioned it.