Would you consider Wisconsin "extreme North"? I would guess not, but I'll chime in anyway. We've driven three times, and have taken three different routes, for various reasons. By far my favorite drive was our first. We left at 3:30 in the morning, and drove for 13 or so hours to Morrow GA, which is just south of Atlanta. We drove on a Saturday, so we didn't have to worry too much about Chicago morning or Atlanta afternoon rush hours. This left us with a nice, easy, six hour drive to Orlando. Our next drive will be in 2019. There's a good chance we'll be leaving on a Friday this time around, so we are definitely going to have to rethink our strategy a bit.
We've also driven east to see the Great Smokey Mountains, with an overnight stay in Greenville, SC. This should have been another 13.5 hour drive, but ended up being closer to 16 due to traffic delays. Greenville is about 7.5 hours from Disney.