There is definitely such a thing as too much. It varies from reader to reader, and from place to place. People on Webtoons EXPECT longer updates; when they click on a comic on that site, they do so, mentally prepared (and desiring) to read longer chunks.
But people on Tapas generally prefer shorter episodes. Even when they want to read a big chunk at a time, they still seem to prefer reading multiple episodes instead of one huge episode. Notice how Webtoons has a "bookmark" feature that lets you save where you stopped, in the middle of an update. Tapas doesn't have that, so if someone wants to stop in the middle of a long episode... that's a bit of a pain to come back later.
If you want to give people enough story to hook them on, so to speak, I would say divide it into two episodes, but post them all at once. Like, upload episode 1, then episode 2 within a minute?