Hello from Minnesota.
I sometimes windsurf in water with ice in it. The water temp can be as low as 32. I can be in the water for hours and still be pretty comfy. Yes, there is a trace amount of leakage, so technically you get a tiny bit of water in around your ankles, but not enough to matter.
I like the BARE Polar Dry Suit. Is is quite warm even in water from 32 to 60 degrees. You have the option of wearing a "sweat shirt" top under the rubber top. This is a one pice suit that slips on. The neck, wrists, and ankles fit with a very fit rubber cuff.
This suit is $400. Very versatile for a lot of things.
I have no relationship with BARE. I just think these are good suits for the money.
You also need some thick scuba boots. I tend to wear 7 to 9 mm scuba boots. Your feet will stay very warm even in freezing water. Any scuba shop can get you these. These also have thick soles to help protect your feet from sharp objects in the water.
I am getting a new water detector soon, and like the detect in the winter when the water levels are lower. I will have my BARE suit on.
Best Regards,
Craig from Minnesota