Approximately 650 standard miles (565 nautical miles). This assumes a route going north through Lake Huron then south through Lake Michigan to get from Detroit to Chicago strictly by boat.
You dry dock it.
I own a boat on Lake Michigan, and am certainly a "numbers guy." Lake Michigan and lakes of this size are so huge that they are measured not in acres, but typically in square miles. The Lake is 22,400 square miles which translates to 14,336,000 acreas of surface area. 5th largest lake in the world.
I think no
Google Maps estimates the driving time as 4 hours and 2 minutes using the Lake Michigan car ferry to Muskegon.
One can use a vehicle to drive around Lake Michigan, an airplane, or a boat.
One week?
I think two of them you can but it would take forever. I'd have more fun driving from Florida to France going back through Alaska!
Boat rental on Lake Michigan is variably priced depending on which company the individual decides to rent from. Currently, such a service can be purchased for as low as $299 for a one day rental, although that price is subject to change.
Take the Grayhound bus.
From Orlando Florida to Portland Texas is 1,163,76 Miles according to MapQuest
Around 50000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000009999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999 miles !