That makes no sense. Why would water on a road at 37F affect a car differently from water on a road at 42F? The properties of water are no different at those temperatures - is there some property of the tires that changes below 40F?
Yes, it's not about the water on the road, it's about the tire's rubber compounds.
High performance summer tires are blended for much stickier higher grip than one can achieve w/all-season or winter tires, both of which have different rubber compounds specific to their purpose. In the cold, the summer tires stiffen up and lose their grip on the surface. Thus I have both winter/summer tires for both my performance cars.
I was out driving on a 45F day back in January (on the summer tires) that was closer to 40F up in the Long Valley area, when I got up there. I had to be very light on the throttle at every stoplight or stop sign to avoid spinning the wheels. That's how bad the grip gets. I suspect that, if one is able to keep the tire temperatures high, it becomes less of a problem. But that's not really possible driving on roads where cannot drive super fast the whole time, and one has to slow and/or stop periodically.
There's other concerns as well. Years back, I got lazy about moving the MS3's summer tires to the basement when I swapped them off for the winter tires. I left them in the unheated garage all Winter. Unfortunately, that turned out to be a very cold winter.
When I swapped the summer tires back on in late spring, and did some typical "enthusiastic" driving, they almost immediately started cracking and chunks of rubber started coming of the treads. This was something I'd read about online from other drivers, so normally I hauled the tires down to the basement.
Contacted Tire Rack about it and wound up exchanging emails with some of their engineers. The conclusion was: don't do that (leave them out in the cold all Winter). They offered to replace them free, but I felt it was my fault since I already knew not to do what I did. So I declined and paid for a replacement set. Have to say I thought they were pretty cool about the whole thing to even offer. OTOH, I've bought a lot of tires, and a few sets of expensive wheels, from them over the years - so it was probably just good business.