[Joe_Nobody]

I'm in a similar situation with my series.

I've released I, II and III about four months apart and now IV is almost two months late. I'm getting emails every single day.

My only advice is to promise quality or quantity. Fine wine can't be rushed...that sort of thing.

 

[Joe_Nobody]

I think the vast majority of readers are fine as long as you communicate.
That is one advantage we indies can leverage in that most "big house" authors can't/won't/don't have the time to interact directly with readers.
I try to answer every email, blog post and comment. I think people like having the author accessable.