You better just count yourself lucky if Cuomo is not the Democratic nominee in 2020.
NYC will keep Cuomo in the Governor's mansion.
The Upstate + NYC minority support strategy could work, but it would work a lot better if NY had an open primary.
Oh that's precious, you think the NY Democratic Party is not bought and paid for.
The party doesn't administer primaries. The State does. And while the dates to switch parties and register and prohibitively far from primary day, voting in NYS with the scan ballot, no ID, etc. is relatively easy. What sucks is the lack of automatic registration, early voting, etc.