Did Hank Morgan dream up his whole experience with King Arthur's Court?

I just got finished reading A Connecticut Yankee in King Arthur's Court, and wow, it was a good book. The ending left my brain running out of control, though - and part of it is convinced that the whole thing was just a delusion of Hank's mind.

Warning - spoilers below (new here, I don't know how this forum generally deals with spoilers)

So, at the end of the book, Hank seems to hallucinate the appearance of Sandy and others at his deathbed, and this got me thinking - what if he hallucinate everything else, too? This would explain a lot of things that seemed strange about the book - namely, his genius in knowing how to build perfect reproductions of every technology in the 19th century; his constructing all of these things from scratch, with seemingly few natural resources; the apparent muddled flatness of every character besides Hank, and how none are really ever explored in any depth, aside from Hank; the gullibility of all the Knights and countrymen, who go easily along with everything he says; the neatly lined up eclipse, which didn't actually happen on the 21st; and finally, the powerlessness of Merlin to do anything at all, making Hank all powerful, until the very last moment, when Merlin can suddenly do real magic (because it's time for Hank to wake up).

It could be that Hank's mind drew up an explanation for the bullet hole in the armour at Warwick Castle, and fit that into his dream. Then the bullet hole would actually have come from Cromwell's troops.

And, perhaps Hank wrote the journal after he woke up or while he was still dreaming. He may have been some kind of King Arthur geek fan, and collected some old Monk-written manuscript, which in his delusions, he used for his own paper (although that's stretching it quite a bit).

The book never really left it clear why Hank went crazy and died, or whether or not the thing actually happened. It made me think of the story as the dream of an anti-establishment American idealist, who has an opportunity to go back and "fix" the problems of the 6th century, in an American way, all by himself.

This would also explain how many characters in the story are able to quote almost directly entire passages from the stories of King Arthur.

What do you think? Could this be a useful interpretation of the book, or is it just my brain coming up with excuses for the strangeness of this story?