I surf through the winter in the UK
I have a 3/2 quicksilver summer suit which is 13 years old and a 2mm rash vest.
Water Temp gets down to 6/7 Celcius - that's 42 F
I surf in Rain, Snow, Fog, once I think the sun shone for 1/2 hour!!
When I've finished surfing, I try and regain feeling in my hands and feet and get my suit off before my legs cramp.
It's a real party!!