Depends on the wind
Once sailed from Toronto (Ashbridges Bay) to Port Dalhousie and back in 9 hours. with half an hour out on shore to stretch my legs. Probably would have been a few minutes faster in a 30-footer. The wind
was honking out of the west and the water
was pretty flat.
OTOH, set out of PD on my way to Port Credit a year or so back (in the short-handed race) and turned on the motor
after six hours, when i was still only a couple
of miles off the southern shore. The dead zone that day was most of the lake.
Basically, if the wind is reliable and you can average 5 knots or more you can be there in 5 hours or less.
Not to repeat what everyone else has said....