Ever taken a trip up the ICW Florida to New Jersey???

I would be looking at nice boats on the Great Lakes as well. You wouldn't be able to take full delivery until spring but it would be a nice trip as well, possibly quite a bit closer depending where you purchase from.

A nice plus is the boats usually have aged at about half the rate anywhere else since they are in a freshwater environment and stored 6 months out of the year or more.

Depending on the size, you should be able to use the Erie Canal during its season, but you'll need to check the length, beam and air draft restrictions. Otherwise it's the St. Lawrence Seaway which can add up to a week in time.

A 355 would have no problem going out that way, tons of boats do it every year to get south from Lake Michigan in my area.

How long it takes depends on the boat, gas or diesel, hull speed or on plane and inside versus outside.

We usually run some on the inside and some on the outiside. Some inside sections cost almost no additional time as you can run on plane almost all day. Central and Northern FL on the inside are not too bad, but you have the gulf stream running with you offshore. We always run St Augustine to Charleston on the outside skipping Georgia to save a bunch of time. Morehead city to Norfolk/the Chesapeake is an easy run on the inside. Weekend traffic on the inside can also slow some sections a lot.

We usually split the trip up going half way from Ft Lauderdale to Myrtle Beach/Southport and then finish a few weeks later. That way we do it over two long weekends and take less time from work.

If you are planning to do this in a 35-40 ft aft cabin, then weather will play a critical role on how much you can run ouitside. Also your range on plane may be limited by your fuel tank size. In our 50 Viking SC it takess about 1400 gallons of diesel running on plane (20 knts) as much as possible. We have done the trip several times from Ft Lauderdale to Baltimore in 7 to 8 days of running time or two 4 day weekends.

Ditto

This idea is soooo much better than Florida!

It really depends where you would have found the boat. The great lakes are pretty self explanatory as far as how to get out, check out a map and start exploring.

Here's a website the state of NY provided on the Erie Canal. If you have sufficient time, it sounds like a real hoot. You can get a season pass for about $75 (I think) and that should cover a fair amount of the lock charges etc. It appears as though a number of towns along the canal offer little or no cost tie-up facilities.

Boating on the Canals - New York State Canals

I've always described navigating the east coast as a college education in boating, something every boater should do if possible. After doing it 27 times, my best time was 5 days and my worst 13 days. With an aft-cabin be very careful of your wake or your radio will be crackling from unhappy boaters and people along the shore. With a gas boat you'll probably have a range of under 120nm. That shouldn't cause much of a problem except for the section between Beaufort & Coinjock in N.C. (150 miles). You'll probably have to stop for fuel in that section which will take you off the channel, costing you a couple of hours. You might want to split that leg and put in around Oriental.
If you do make it up to the lakes, the Erie Canal is a beautiful ride, most of it at slow speed. Plan your stops carefully as some spots have nothing but a dock with no water or power. Also, some of the docks are spaced pretty far apart. So make sure you can get from one to the other during your day. With an aft-cabin you will not be able to make it all the way to Tonawanda. You'll need to grab the Oswego Canal and go through the Welland Canal. Bring your passport. When I did the Erie a few years ago in a 40' Express it took 5 days and barely over 200 gallons of fuel from Buffalo to Albany.

Whichever route you plan to take, schedule in some down time. Weather doesn't always cooperate, and the worst thing for the spouse in getting her to love the boat is giving her a white-knuckled ride.
Breakdowns do occur, from a simple filter change (you can do that, can't you?) to blowing something that may need a hoist to remove.
Never did the northern trip, but have run the ditch a few times. You can take the inside which is a cool ride the first time or two (will take more than a week), or run outside for better time. And you can/should stop each night just to keep your wits and get on terra-firma. It is pricey with the fuel, dockage, provisioning, parts, etc, but this is a long ride. Cutting across aforemetioned sounds, they are open water and do kick up in the wrong winds. And help may be a few hours away.
But plan away, set your course, and follow your dream. It will be rewarding.