I've seen posts that they are catching tog there now. Just a matter of viz, so if we get a dry spring mid May should be fine. It's been years since Iv'e dove it, though. Maybe someone with more current experience there will chime in.
In my younger days I'd dive water in the 30s and 40s, under the ice, and all that but I know what you mean about water temps. I used to dive a drysuit for that kind of water. I'd dive now just to try out the 6.5mm OMER freedive suit if the air temps cooperate. Hardly any if any water at all gets into a good freedive suit. I think it would be okay except for the face. Brrrr.