OK, here's another of the "what's my chances" threads.

Planning on flying to SFO later in the winter. I'll be Plat (currently Gold) and she's nothing (with NW, that is).

I can fly either through DTW or MSP.
I can fly any day of the week -- actually, mid-week is preferred.
We like to start out later in the morning or early afternoon.

What would you suggest as the best shot, given that I'd have to buy the tickets a couple of months out (so no checking availability the night before or any of that stuff)?