@Marschall67 Are you looking to have a shop do the work or do the work yourself. If a shop told you about 2 ohm in a C6, many factory Bose systems are 1-2 ohms, but the C6 seems to be closer to 3.5-4 ohm when measured, so I suspect they are generalizing about Bose systems, aren't familiar with the specifics of the C6, and I would be hesitant to let them touch the car.
I've been researching a stereo upgrade and the general consensus is to just replace the wire. For the $20 or whatever you'll spend on some decent copper wire, you'll get better wire, easier speaker and amp terminations, easier install since you just have to fish the new wire, and more amp mounting location options.