Dan,
I took a look at the Nov trades on CQG last night as I was turning in, 5 out of the 6 lots traded on spread. That's where the liquidity is, so cover there, and then it's up to you what to do with the Jan shorts. If it was up to me, I'd cover the whole damned thing and walk away - lesson learned.
You'll see much more depth in the spread than Nov outright, and don't be tempted to screw around.