The Pines is pretty miserable in the winter. When it's wet it throws up a fine silt/grit that grinds bike parts (and body parts) in a remarkably unpleasant way.
It also holds water and drains badly so it's pretty much 50% silty puddles on most of the trails, even if you go off piste.
I ride there most weekends over the winter and it's always a joy when it dries out in May and becomes the sweeping single track haven we have enjoyed for the last three years.
Certainly for a group ride on a wet Sunday in Feb it would be a shadow of it's spring/summer self and I wouldn't feel I could really encourage people to travel to it, especially if they had been before and were expecting fast singletrack. You can get the same wet muddy experience on any local bridal way to be honest
I would be much happier keeping it a spring/early summer event as it's a bit of a tradition now and that would certainly offer the best riding experience.