I'm voting for "Hast thou a blog?" if one wants to use period English, but I'm going by feel. Does anyone actually know?
May I suggest looking in period literature? If I Google Books "Hast thou a ", I see in the first page of results hits from John Bunyan, 1678-1684 and William Shakespeare, c. 1591, among lesser lights.
Here's the new thread for posting quotes, with the usual rules: