Driving time is about 25 minutes each way on the Greeneway, depending on just where at WDW you're going to/from.
Security lines really vary. My wife flew back last Monday. At 5pm, she waited 50 minutes in a security line to go to the Delta area - gates 60-99. On Thursday, also at about 5, I was in line for less than ten minutes.
Two tips - first, don't rule out curbside check-in. It may be significantly faster than waiting inside.
Second, at security, look at the lines carefully. One line may be feeding two security checks, while others may feed just one. Obviously, the latter may move quite a bit faster.