I have the same problem this year.
Normally I have my plants outside.
From every kind I store one or more plants in my basement till spring.
Because I sometimes lose one in my strange winters here.
So I stilol have one. But this year it was something wrong and all inside started to grow. So I have to grow them inside, because we have 2C outside. It was very nice now 2 weeks, but it turned and getting cold again. So hopefully the others outside didnt start to grow.
My Medium I use for them inside is, about 40% Seramis, 40% pumice and mostly a mixture who is for grow on the roof of houses. and 5% Perlite.