I'd say about 10 minutes to DTD. It's quicker if you get on I-4 going back east by the way rather than taking the roads with all of the traffic lights, mainly because traffic on the Disney roads and the lights can really slow you down.
Take Old Lake Wilson north to US-192 east to I-4 east...exit #68...make a left at 535/Apopka/Vineland road...then another left almost immediately at Hotel Plaza Blvd. It'll dump you out right at DTD from the north end, avoiding all of the lights and traffic.
It's taken me as long as 15-20 mins last time I went the "slow" way, mainly because there was an accident and the roads with the lights were super clogged up with traffic when I went that route so I've started using the I-4 route instead, it's MUCH quicker! (That way goes up Buena Vista Drive past many hotels / lights and such).