Sorry I re-read my post and I don't think I wrote what I meant to say lol.  Apparently you can now book sites at Mew Lake via the online reservation system for winter dates.  In the past you have never been able to actually reserve a site as they are all first-come-first-served.  Apparently Ontario Parks has just started doing this at a few parks.  I wasn't referring to the winter rules, but I totally see how my post looks like that's what I was asking (sorry bout that!)

No worries Token!  One of the things I like about winter camping is going up there and pretty much having your pick of spots.  Maybe they'll just leave the hydro sites as ones you can reserve.  Winter camping is getting too popular now!

Yes they plow the sites at Mew Lake (in the hydro site area) all winter so you would be able to bring a trailer in for sure.

Rob H wrote:

Trailers and R.V.'S are quite popular in the Winter and based solely on my rather unscientific observations, the nicer the trailer, the less people spend outside.
Martin take the trailer and enjoy. 
Not to totally hijack the thread and I know it is against the regs to forage firewood in the developed campground but is there any reason I could not take the sled and head out into the airfield and bring back some standing dead fall to fuel the fire?

I asked a warden a similar question when camped in the Rock Lake Camp ground this past spring.. I had my canoe with me and asked if I could canoe out onto Rock Lake and harvest some dead wood for burning as if I was at an interior site and paddle it back to the camp ground to burn. He told me in theory that it is acceptable but his issue was with other people seeing me do it. One person sees me burning dead fall and then they figure they can grab it from around the camp ground area, then someone else does the same because of the last person etc. Basically go for it but try to not let anyone see you do it.