I have a one-and-a-half episode buffer, which is much shorter than I need it to be. I'm trying to build it out, but as I develop a better sense of pacing, my episodes are getting longer instead. I'm easily spending two weeks on each episode, rather than one, which means building up a larger buffer is just... not happening. 
Buffers are useful for a few reasons. They lower your stress levels, because you never have to worry about being 'late' with an update. They give you room to have a break if you find yourself unable to draw. (Something I'm currently struggling with, because I don't have enough buffer, and so I can't give my hand and wrist proper rest...) And finally, they give you breathing room to re-do early episodes if you so wish, something which can help draw in new readers. (Since most readers decide within the first few episodes whether or not they will read on and sub.)
It is frustrating not being able to share things which are finished, but not released yet! That said, you can put them on a Patreon, or share non-spoiler-y panels from them on social media as a form of advertising for your comic... So they can really come in handy there!