Sounds like a good idea, but there can be complications that should be thought through. Number one is the number of trips you might end up making to go look at boats in far away (expensive) places before finding the right one, and possibly settling on something less than ideal because you just spent a lot of money to get there. When you do find the right one, then you need to very carefully and realistically assess what will need to be done to it (you said 20 years old, it will probably need a lot more than you or the surveyor originally think) and what local resources are available. If you are going to do a lot of the work yourself what are you going to use for tools, and where can you actually do the work. If hiring it done, again, what yards are available and what is the cost; will it be an offshore trip in an unknown boat to get there, are you OK with that? If you end up making half a dozen trips to find a boat and then several more trips for you and the family after finding the right one, the cost of the boat has gone up substantially. If I were taking my family offshore I would want to know my boat inside and out, every system, every hose and clamp, wires, batteries,
rigging, sails, etc. This all takes time, and with the family on board wanting to "go", it probably won't happen. I know this sounds negative, I'm not meaning it to be, but buying a long distance boat can be challenging in a lot of ways that aren't obvious. On the other hand, the Washington and Oregon coast is no picnic either.
Good luck to you and your family and let us know how it all ends up.
John