DON'T SELL THE HOUSE! Instead, do what many others have done in the past and either get one of your kids to house sit for you, or if you feel comfortable about doing so, rent it out for a year.
Next, be sure to get a boat large enough to be comfortable, but small enough to singlehand sail. Something in the 30 to 35-foot range seems to work best for most folks that have done the same thing in the past.
The most difficult part about all this is you must consider that you'll be residing in the same amount of space as your living-room with individual rooms smaller than a walkin closet. Your bathroom will also be your shower and in order to take a shower you'll need to put the toilet paper, towels, and anything else you wish to keep dry in a water-tight container. And, you only have a small volume of water to work with, so that shower will have to be well planned and very quick or you're rapidly run out of water--women don't like to take short, and sometimes cold, showers!
The amount of things you can take with you is also quite limited, which is not my wife's idea of a fun way to cruise. Most ladies want to take an entire wardrobe, lots of shoes, a couple matching purses, etc... Most of this will NEVER be used, but that does not count. As for me, I can get away with a pair of flip-flops, a pair of boat shoes, six pairs of shorts, two pairs of jeans, two hats (one spare), and a half-dozen shirts. One pair of socks is good for the entire year, and of course, a change of underwear for each day of the week. Your stuff will easily fit in a small duffel bag--her stuff will consume three, large, steamer trunks.
Bugs are the biggest problem I encountered--even on week-long voyages. The flies gnaw your hide down to the bone every day, and when the sun goes down the mosquitoes and no-see-ums find their way through the tiniest openings. You'll need a liberal supply of skin-so-soft in order to survive in the sunny south. Fly swatters are also a good thing to have onboard at all times.
After six or seven months, one of many things will ultimately happen. 1. She'll become a raving lunatic and hack you to death with a machete. 2. She'll escape the confines of the boat, find the nearest airport and fly home, where she'll quickly file for divorce. 3. She'll love every minute of the adventure, want a bigger boat and tell you to sell the house. Option #3 is unusual, but it has been known to happen.
In my case, my wife will NOT be accompanying me on the voyage to the Florida Keys this coming October. Instead, she will wait patiently for the month it takes me to get there, then when I'm comfortably tied to a marina dock, she'll hop on a plane and fly down to Marathon Key to spend a month or so on the boat and sail around the keys. When she tires of living in the cramped space she'll fly back to the frozen north to play with our 4-1/2-year-old grandson.
Good luck and I sincerely hope everything goes the way you wish,