Powering 17 meters of RGB LED strip - Worried about voltage drop and wire size
I'm going to be wiring the rows up snake style and dual feeding to keep brightness consistent across the array.

If Dual Feeding is what I think it means, you already know what to do.

Feed the 5v to each 106cm section individually or in pairs. Don't chain the power through the entire 17m length. Sure, this means 8 or 16 sets of 5v and Gnd cables, but with each only carrying 2A or 4A over a small length, heat/current/resistance issues go away. Same reason you only see 18 AWG wire in ATX Power Supplies. Instead of a single 10AWG 12v Cable, it uses 8 or 12 18AWG wires to carry the same current. 

You would keep the data cable the same. Just make sure to tie the grounds together.

Actually, pretty much how the datasheet for the Sparkfun item you linked to already has it, for a snake layout.


For 1M strips (106cm = 1.06M) the voltage drop would be insignificant.