Wade has already won big, divisional games on the road. As someone has already said... the win at FedEx last year was sorely needed even though the Commanders are a dead team walking and were last year too.
He won in 2007 at the Meadowlands to complete a sweep of that year's eventual super bowl champion. He also won at Philly by a large margin (38-17) in 2007 (the Witten helmentless game).
Not to mention he won the huge matchup of two 10-1 teams playing in week 12 of the season (Green Bay in Dallas).
Even last year, he took his team to (again) the eventual super bowl champs house in Pittsburgh and had a badly beaten up team ready to play in 15 degree weather... even though he was down to the third string RB, his pro-bowl TE was gimpy as hell, his QB was still recovering from a broken finger on his throwing hand, the whole team was a study in poor chemistry and his primary receiving weapon was unable to beat anyone not in a 49er uniform. Dallas very well could have won that game. Had the defense not allowed a lucky bomb to Santonio Holmes, Romo wouldn't even have been in the situation where he threw the game clinching INT. They were thisclose to taking Pitt out in their stadium, in their weather, with their fans waving those damn rags.
Phillips did his job.
Not to mention beating up the Giants in last season's second game against them... a game Dallas had to have. He had them fired up and ready to play, even though there was a LOT going against him (see the Steeler game above).
No, I'd say that Phillips has proven he can coach in a big game.