First suggestion....join the Deep South Koi and Pond Society.
http://shesplayingkoi.wix.com/deep-south-koi they should be able to provide lots of local tips and advice.
The Intex pool should be fine with good filtration. Be sure to clean the pool before adding fish. You should be able to drape the entire pond, filter, and pump in a clear pool cover (heavy duty bubble wrap). You can also put in one or more titanium 200 watt heaters that should be able to keep temps at or above 50F.
http://pentairaes.com/200-w-30.html
I did similar when we moved our koi from Dallas TX to Atlanta. The koi were in a tank on the back patio through our first winter. We get much colder and for longer than you do in along I-10.