I'd doubt its anything to do with colder weather. If anything, your engine should be colder and less prone to eating plugs.

What are standard plugs rated at on the heat scale?
 
Can't really comment as i upgraded the plugs on mine not long after getting it but I would give NKG BKR7EIX plugs a go, seems to have sorted the missfiring for others, either that or get the coilpacks checked.
 
Get some NGK BKR7eix spark plugs. When I got my revo map done the guy said get them as I'll get mild misfires under hard acceleration which I did twice. So I got some and no it runs perfectly :) highly recommended. Best off looking on eBay for the best prices :)
 
Is that resonated? I think that looks and sounds spot on. Really want to get myself this car-back. Will need to see how funds look post-Christmas.