Depending on your browser, that seems pretty doable with a plugin. I assumed ad block plugins would nuke video ads anyway -- is the issue that they are preroll and hard to filter?

At the risk of getting into an ethics debate, that's sort of the deal being offered by the publisher: you get the content in exchange for watching this ad.

How else are video content providers supposed to keep the lights on?

.. besides not using commercial ads and instead using image / text ones that take up much less precious bandwidth.