Schrodinger's Novel

So as mentioned, I’m doing National Novel-Writing Month, and the words are pouring out.  Whether they are coming out as liquid silver or pea-choked vomit remain to be seen, but I am 34,700 words into this draft already, cruising quickly into the second act.
The void is killing me.
I think that’s why I like short stories; I write 6,000 words at most, and when I’m done, I hand them to a crit group, and within two weeks I know how well I did!  Anybody can get through a short story.  It doesn’t matter whether the feedback is bad or good; I just like to know how much work I have to do.
But this novel, man…. I used to make Gini read my novels chapter-by-chapter as I wrote them, but then I realized that no human ever reads a novel like that.  (Here, read a novel over the course of four months, in erratic drabs that have nothing to do with your interest in it.)  So instead, I let her read my larger works in larger pieces – I usually try to get to the end of it, but what’s happened is that I get to a point where I’m not certain what happens next, and I can’t bounce ideas off of Gini until she knows what’s going on, so she winds up reading the first third of the novel so I can figure out how to get to the second third.
Gini, however, is involved in a crushing project.  She will not be available until mid-December.  By which point I will have hopefully finished up Act II, and be well on to Act III.  I may even be completely finished by the time I make her sit down for a weekend and read it.
In other words, I’m writing this whole novel without knowing whether it’s any good at all.  And I’ve sort of abandoned the idea of writing a salable novel, but I would like to know whether the novel I am speedily plopping onto the page is going to require seventy rewrites or just a touch-up.  Are my characters likeable?  Does the plot have too many whafucks?  Is it interesting?
I am driving blind down a foggy path at seventy MPH.  I hope I’m on the right path.  But there’s no markers to tell, and eventually I’m going to coast to a stop and discover whether I’m at my destination, or stuck axle-deep in a boggy marsh.
That’s kiiiiinda scary.