I would probably choose M11/NCR. Whichever route you choose is liable to severe delays at that time; you need to be flexible when driving in London!

The North Circ should be fairly free from traffic between the M11 and Wood Green although there are sometimes delays around Edmonton. There will then be traffic from Wood Green until the next bit of dual (usually about 10- 15 minutes all told. You might be lucky on the approach to Hangar Lane and will be held up a bit towards Ealing.

The M25, should be OK until you get to the western bit wit the roadworks which can be horrendous (the A312 through Watford is a possibility here).

I think the North Circ is likely to be quicker, and it's easier to get off it if you encounter problems. There's not a lot in it, though.

I think central London is OK if you know the short-cuts and can be stressful. I'd avoid it unless you're confident.