I guess this means no. 50 or below. That is unlikely to happen anytime soon. Besides I put down my best pass at BMP at the last track day and it was humid and in the low 70's high 60's and I drive a boosted car. I do not think weather that cold will actually help you on a N/A car. Tell your boss you need the 19th which is a Saturday off and lets see what it will do.