Just to chip in here; there are a couple of diversions at Drumlanrig too, although they only miss out one short section of singletrack (and add in a wee bit of s/t and about a Km of fire road.
Rode round it this morning in glorious sunshine then snow then glorious sunshine again, so it’d be wise to expect any weather.
As has been mentioned it does get ‘a bit’ slippy in the wet; you’ll need to actively ‘ride light’ over the roots and definately don’t hang back, speed is your friend, if you slow down to pick your way thru you’ll end up stalled or pedalling on the roots which will spit you out sideways. You can expect the wheels be going sideways quite often, just expect it and don’t get gripped, trust your tyres and don’t use the brakes unless you have to, especially thru the roots. Have fun!!!