Assuming consciousness is an internal state (nothing mystical or metaphysical), isn't this the same thing as a long nap? Ie, is the fact that the you after a nap feels like a continuation of yourself of no benefit to the you before a nap?

Of course, the analogy isn't perfect since brain activity does not cease during a nap, but consciousness does.

You can say that for any attempt to make plans for the future.

Sure, but you can say the same about going to bed at night with the intent of waking up in the morning.

If you extrapolate this notion, which is something I have done and find an interesting theory, then consciousness is really a moment's event, like a processor's tick. Every tick you sense things, retrieve things from memory, and serialize a bunch more things into memory (including the working memory of say, a conscious movement you're doing right now.) The next moment another "you" comes along and lives that moment. To me it's the only point at which I can draw this line of "when is it no longer you?", as in being cloned with an exact brain snapshot, or sleeping at night, etc. You are only ever you for that single moment, so what difference is there between the revived you and the you a second from now? It's also a convenient belief in that I feel free to do teleportation when that becomes available (pulverize your body here, recreate your snapshot there.)