-Maybe Colorado and Massachusetts
In order to win any others, he'll either need a Clinton scandal, or an enormous burst of momentum (winning NH in a landslide, pulling off an upset in NV, and doing much better than expected in SC.)
Pretty much this exactly. Vermont will vote for Sanders even if he's dropped out (see Dean 2004), Minnesota looks pretty favorable to him, but it will almost definitely be a single-digit win either way. Colorado and Massachusetts are theoretically good for Sanders, but he'll have to pull up his poll numbers there before I would give him a better than 50-50 chance in either.