I'd be phoning the circuit daily to check that it's still on. We had a test & race day cancelled at Anglesey this weekend due to a frozen circuit and light snow.
I'll be there with two cars, a few novices and a few PHers from the SW Forum.
I'm going to give the circuit a call on Friday to check, should be ok though. If it's icey, just go a bit slower until the track warms up from use then balls out after lunch. Only settled snow will stop it.