Multiple Methods for Sending Stereo Signal to FOH?

If you make two adapter cables (or can find exactly what you need in a commercial product), you can do it. If you look at pre-made cables, make sure they are wired correctly)

you would need XLR to two mono 1/4" (one XLR pin is ground, one pin is Right, one pin is Left)

[Blocked Image: http://ecx.images-amazon.com/images/I/21BzZsXS3uL.jpg]
The above picture is to show you the look of the cable - I don;t know if this particular one is wired correctly or not. You would need XLR Male for one cable, XLR female for the other.

OR, if you have one spare 1/4 balanced line available in your snake, you could use commercially available "TRS to two mono" adapters on both ends Tip = right, Ring = Left, Sleeve = ground.

[Blocked Image: http://ecx.images-amazon.com/images/I/41E42fFh%2BKL.jpg]
The Hosa STP203 is an example of the correct cable.

OR, You could run a separate snake.

OR, two channels of wireless?

you're welcome

You could send an unbalanced stereo signal down a single XLR channel by writing the 2 pin of the L/R XLR outs to the 2 and 3 pins of the XLR (the 1pins can both connect to the 1 of the adapter, leave 3 unconnected) connector that connect to the snake, you will then need to make a breakout cable on the other side of the snake wire with two 1/4" jacks, wire the 2 pin of the XLR to the tip of one Jack and the 3 pin to the tip of the other, the sleeves both connect to the 1 pin.

Good luck,
JT