Chapters and episodes are different things to me.
I came from wattpad, so I write chapters- between 3k-6k words. Which is great for that forum.
Tapas markets itself as entertainment in bite-sized chunks- they want episodes that just take a few minutes to read, which to me usually ends up about 1k words (or during contests 500 words cause you've got to get that episode count xD).
I take my chapters and chunk them out into the bite-sized episodes Tapas wants (though my writing has changed a bit since joining Tapas and I'm starting to find the length of episodes more natural) and just labeling them as 'parts' of a chapter (ie Chapter 1.1, 1.2, etc.).
I don't find it necessary to upload them all at once, otherwise it defeats the point of those 'bite-sized' episodes if you're still giving people large chunks of content. I find more consistent schedules of measured updates keep readers more engaged- you can even schedule them if you have the whole chapter done.
Just make sure if you're splitting up a longer chapter, you pick a natural spot to break into the next episode!