Do I wake or sleep?

I can't do a search on CMS for it because I'm not a subscriber but here's another style manual that says (in the Punctuation--Quotation" section) "when the question mark ends the sentence, the period is, of course, omitted." (I can't do a C&P because it's a .pdf document.) The period is assumed because it looks very cluttered if you spell it out. A good amount of style is how things look on the page.