OK, that's a bit further out then we usually stay, but I'd think your best bet would be to take 27 to I-4. From there, check traffic maps. I don't think I-4 is packed like major cities in morning rush hour, but it has traffic. If so, you can jump off I-4 at several different spots to hit WDW...429 north to Western Way would be the best alternative. As for the best way to enter the parking lots, it'll depend on where you get off I-4. There are a few exits. The signs will be clearly labeled...both on I-4 and when you get off. Like I said, WDW entrance is more like a highway. In many spots it's 4-5 lanes wide and traffic flows 55-60 mph. Follow the signs to the park of your choosing. One tip...when you get to the parking lot toll plaza, if it's during morning rush, everyone seems to go for the middle booths. Look far left or far right for a much shorter line.
Yes, for Flight of Passage, you'll need to show up incredibly early if you don't want to wait in line. But trust me, for Frozen, not necessary. Until about 10:30am, the line is very short. We were there just a few weeks ago. More than once, we got to the ride between 9:30am and 10:30am and never waited more than 10 minutes...one time we literally walked right on. They don't give out FP+ for that ride until 11am at the earliest, so from 9-11am it's all standby. Keeps the line really short.