Should we consider a different boat for the Great Loop?

Let me start with the fact that we love our Beneteau 473.  It is almost everything we could want in a sail boat for the Great Lakes and even for ocean sailing (I think).  One downside for our family is that we only have 2 staterooms and our kids can't seem to figure out how to share a room with a king bed.  Long gone are the fond memories of them sharing a small V berth in our Allmond 31 wanting to hold hands with each other to fall asleep.  

Looking at our boat we decided that our two stateroom sail boat would not be ideal for our family to live on for a year and do the loop in for a number of reasons:  

1. There is not going to be much sailing on the loop route (though I would love to once we get to the Bahamas) 
2. We will have to ship the mast for the western part of the trip from Chicago to the Gulf & then again going through the Erie Canal system.
3. Teenage kids need a bit of their own space so we really want something with 3 cabins
4. Amy requested a Washer/Dryer
5. We don't currently have a great place to store a dingy other then on deck and in the way of things
6. We don't have a cockpit enclosure

Personally I would prefer to take our boat and address the above issues but unfortunately if we want to squeeze in a major family adventure together before Annabelle goes to collage we needed to do it this year as she really wants to be back for her Senior year.  While I think I could get all of the above addressed as well as a number of other projects between May and August it would be tight.  Not to mention all of the other stuff going on in our lives plus the addition of the two exchange students we have living with us this year doing all their senior activities and other stuff they would like to see/do before heading home in July.

This means that we need to buy a different boat, get it to our area of the Great Lakes, make any updates/modifications, and leave by August so hopefully we are off of Lake Michigan by the end of August or early September.  Lucky for us we live between Detroit and Sandusky so there should be lots of boats within a few hours drive to look at.  Hopefully we can look at boats around our area to help narrow down what we like and don't like and maybe even get it down to a certain model/year then expand the area to find the perfect boat!  

So what do we want?  It seems we are going to transition to the dark side and consider a power boat in an attempt to have a smaller draft and more comfort.  I would like a fly bridge and a pilot house to navigate from.  We would like diesels, a generator, and a place to store the dingy.  The kids both requested their own space which means we need something with 3 cabins.  Amy requested a washer/dryer and a big refrigerator.  Unfortunately, as we started digging though yacht world we found that to get 3 staterooms in a power boat put us into something in the 50+ foot range more often than not.  Seems when you get to that size then hight also becomes an issue as the lowest bridge we can't avoid is 19ft.. Ideally we would like something that will get under 17 or even 15.5ft bridges which would allow us to take the boat though downtown Chicago and the full length of the Erie Canal (If Canada does not open next year).  I suspect we will end up with a trawler of some sort but I'm sure we will look at a lot before we narrow it down as Amy has not been on a lot of boats and like I said before we both really like our sail boat.