I have used this plugin multiple times, it is great and easy to use!!
Sorry I don't know if this is the right place to suggest a feature or not, but I didn't see any forums on the pagenavi homepage. And maybe this is already possible somehow and I just don't know?
Would it be possible to set a page maximum and page minimum, so that if you don't end up with 10 post on page 1 of 1 and then 1 post on page 2 of 2. Could you set a page minimum to something like 5 and a page max to something like 10. This way if there are 11 posts the page min for page 2 of 2 would be 5, therefore 6 posts would display on the page 1 of 1 and 5 pages would display on 2 of 2.