I participated in NaNoWriMo this year (first time attempting at a novel as well). Managed to hit 20K words, but the story went nowhere and I lost interest by the end. Might pick it up again someday again.
If the doubling the word count seems daunting, you can try rewriting your 20k words into a short story and still get something out of it.
If you're anything like me you'll probably never return to finishing the novel and it'll rot on your hard-drive for years to come. At least if you package it up as a short story it'll be just as rewarding as a completed NaNoWriMo.
Then if you're happy with it you can still publish the short as a kindle ebook (Which can probably be completed by the end of January and you'll start off the new year accomplishing significant.)
