The test centre for Mod 1 is probably the best surface you'll ever ride on.
Unless frost / ice is still on the centre test pad, it should still go ahead.
Take your time, have faith in your tyres and allow for the conditions.
And most of all ... good luck.
That's a shame.
I quite liked her naïve questions - I've been lurking on the sidelines for a while and she asked a couple that I was thinking of, but didn't want to ask.
I do hope you're wrong, younger bikers are few and far between.