In February, we crossed at Windsor for the first time (we usually cross at Buffalo and then drive across Ohio and hook up with I-75 in Cincinnati -- we've done that for many reasons, shopping along the way at certain favourite store in Ohio a big one

) -- we crossed the border around 8:30 a.m. (yes, we left TO very early.....) and we spent our first night in Knoxville TN; we got there around 5 pm. DH and I were very tired so we didn't push it any further and we knew from experience that once you get past Knoxville, for a while there aren't many hotel choices. We wanted a decent hotel and a good southern bbq dinner, then a good night's sleep
You can make Knoxville to Orlando in one day, assuming no construction delays etc. -- last August we left Orlando and made it all the way to Knoxville on our first day driving home. So that would mean only one night on I-75.
Also, if you don't already have it, I HIGHLY recommend getting a copy of the Driving I-75 book (by Dave Hunter). You can find it in most Chapters etc, but here's a link to the book's site:
http://www.i75online.com/
We absolutely wouldn't hit I-75 without it -- we LOVE this book. Our older version is totally scribbled in, with exits circled, stars beside certain things, etc. We just got the new copy recently. The book is so worthwhile.
Have a great vacation!
