if its an actual cyanoguttatus then i would say that they may be ok, the only thing with the temp stuff in the wild compared to in captivity is that usually they are in very deep ponds so that although the top temperature may be very cold the bottom temperature actually stays warmer since its more insulated which is why natives move into deeper water when it gets cold, but if a pond is only a couple feet deep then the temperature is pretty much uniform and if the water is too cold for them there is nowhere for them to go that is warmer, i think they should be fine but i would keep a close eye on the water temp in the winter and if it goes into the low 60s i would bring them in, and i also wouldnt put them out there right now when its getting cold, put them out there in the spring so they have a chance to fatten up and get used to pond life before having to get used to the colder temperature