Saints fan here. I think the Saints/Cowboys game will be a great game, but both teams do have some work in the next 2 weeks.
Anyway...
You're not too accurate in your assessment of the Saints this year. They do some 5 step drops and empty backfields, but they also run way more 3 step drops, screens, draws and shotgun formations, and they even max protect a good bit. Honestly, they aren't as much of a "spread" team as say, the Patriots.
They are also 5th in the league in rushing, and both Pierre Thomas and Mike Bell are pretty physical.
If there is a way to beat the Saints offense it is mixing up pressure...Brees does not like pressure up the middle, he likes to step up in the pocket. Jam recievers, try and get Brees to step back or to the side, and limit the running game. I don't think it really can be done, but that's what I would do I guess.