Agreed on not getting cocky, but I'm not so sure about the D +6 sample. It's that special time of year where pollsters want to save face.
As far as a President not really wanting the office anymore, sadly “Big George” H.W. Bush admitted that if he’d known what a stain that Clinton would be on the Office that he would have run harder. The reality was that Bush had to assume a lot of the Presidency during Reagan’s second term, so after four years as the official President, he was spent, and more than a little burned out.