A friend of mine had a 23 foot C&C that I crewed on based out of Kennewick on the Columbia River. Fun times so long ago. If a tsunami ever hit the coast I can't imagine anything that floats surviving. You have a lot more faith than I do.
I realize not everyone can afford a second or third survival vehicle so if it's gonna have two wheels I would definitely get a motorcycle so your wife can ride behind and hang on to you. A motorcycle would have the power you really need and a suspension to go off road when it becomes necessary. There are ways to attach a trailer to a motorcycle and you could always detach it and leave it behind if things got impossible. Just plan on having fun on this bike you plan to build and it will take your mind off "the big one". Best wishes always ...................michael