During NaNoWriMo, the challenge of the word count hangs over us. Take advantage of it and wander down those tangents. Explore a tickle of an idea. Flesh it out. Does it work? If so, keep meandering. If not, that’s okay, you might be able to use this as a short story or as extras for your website during the promotion of your book later.
Maybe the off-beaten path you’ve just beaten is really your story, not the one you were writing. Or a sequel. You might not have considered this as a series, but it could be. Why not?
Tangents can also help you with back story, character descriptions and personalities, worldbuilding, opportunities to expand your story and your thoughts about the story. You can slice and dice in the editing process, but if the call to deviate pulls your fingers in that direction, go with it for a while and see what happens.
Keep an open mind and let your unconscious lead you in what might be the right direction.
If it isn’t, your mind will pull you back automatically, so don’t worry. Keep writing.