1. There are several NFL qbs that have contracts that expire after this season. Sign one of them. Cousins is on a one-year deal, for example. If he doesn't get the VIkes deep into the playoffs and maybe not to the SB, likely he'll be let go. (Understand, I'm not advocating for the Cowboys to sign him, just noting possibilities).
2. Trade some players under contract and draft picks for a high pick next year and draft a quarterback.
3. Go with Rush. After all, he's better than Dak, right? (Tongue in cheek comment, to clarify).
Pick your poison...