Thanks all for your input and ideas. I had done some previous research with voltage drop calculators, but could not find anything specific for cca wire. It may use the same calculations as pure aluminum wire, but I'm not sure. Either way, it does not look like 10 ga cca is the best for a 30' extension (and yes, I too am surprised they would use cca speaker wire).
Here is a link I found this morning that some may find useful to help determine cable size:
Using this tool, 10 ga cu would be adequate for 30'. But when the camper or trailer wire length (to the controller) is added, then it jumps up to 8 ga in my application if I want to keep the voltage drop to 2% or less.
At this point I plan to make an 8 ga 30' extension with Anderson connectors on either end.
Thanks again for all your input- Bob