The advise given here is all good. I will try to put it in other terms for you and the rest of the community that reads Sailnet that are contemplating such a move.
Lets talk about sailing first. Seeing how you and your family are not sailors, I see this a big problem. Gigantic problem actually. Sailors for the most part are a different breed of humans. Even more so than powerboaters. We are in a class of our own. Taming the wind to our will, managing the boat and the labor required is not in most peoples skin. The romance of it all in movies, books and occasional sailors yarn that most people see is very misleading. It's work. A lot work. Both in sailing, maintaining even a simple boat and living on one. Nothing can compare to it that I have come across in all my adventures. But for us sailors, there is a sense of pride, accomplishment and love of the lifestyle that is hard to explain to the average person. Can you learn to love this lifestyle, you bet. However, not by giving up everything you know about living, lifestyle and managing everyday life as a landlubber. In order for this lifestyle to be successful, it needs to be taken slowly, methodical, and great care. Jumping in with both feet into this abyss with no knowledge of what it really takes to live is tomfoolery.
The expense of it all. Tons of books, articles in magazines and discussions on various bulletin's have beaten this subject pretty hard. There are roughly 3 camps out here on the sea; simplistic, moderate and luxury. From your post you will fit in the simplistic camp. This means living like camping in a park at worst to living in a small RV at best roaming the countryside. One will need to buy an older boat with few systems and need of repair. Skills to fix and maintain this boat will be required. Upgrades to systems can be very expensive. The term B.O.A.T stands for Bring On Another Thousand. I found this axiom to be to true. Than there is dockage and insurance. This can vary greatly depending on location. Major cities or popular locations are the most expensive, average > $600 a month to rural areas or private docks, $300 for the season. The problem with rural areas is finding work or having to commute great distances each day for work. Of course there are exceptions out there just have to find it.
The lifestyle itself. The boat is a floating home; constant in motion, small ( some prisoners have more room than we do), no privacy, constant boat maintenance, wonderful sunrises/sunsets, great sailor folks to be around, one with the sea and the environment to name a few. Each sailor has their own experiences and the same. This lifestyle will test a marriage/relationship like no other. Living in close quarters requires all norms to be thrown overboard. Privacy can be the most treasured commodity on a boat. Virtual privacy will be a new word in your vocabulary. Simple things like storage, cooking and cleaning will take on a whole new meaning. No longer just going to closet or cupboard to get things or even store things will be as simple as living in a land base house. It is different. I believe it is a whole new genre one needs to get used to. Point is what is simple on a land base house can be complicated in a boat. Taking a shower or going to the head is different. It is no longer just pushing lever or turning on the water for a 20 min shower.
Without writing a book here, I just want to point out a few things one needs to consider for such a radical lifestyle change you asked about. Take the advise others here and elsewhere. Weigh them with reality of your life at the present time. Keep asking questions until you are satisfy so an intelligent decision can be made. I wish you all the best and luck.
Catalina 445, Hull #90