at this point there is at most 10% downside to NG and as much as 100% upside. Jan is looking to be about 2/3 of the month below avg temps and 1/3 slightly above for most of the gas using states. Below $3 NG with inventories at their avg would be extremely unusual for a Jan in these conditions. Only reason that NG has fallen so much is Oil imho.
With a colder then normal Jan I am almost certain it will retest the $3.80 area of past resistance. Getting into the $4's again will depend on how the temps play out towards the end of Jan and beginning of Fed.
There is no short here. Long trade make the most risk/reward sense.