I can get this much:

>! [![enter image description here][1]][1]

which is to say,

>! 25 cells.

Here's how it goes.

>! The green and red cells are, respectively, mine-free and mined. We begin by counting cells near the 3 in the 321 configuration to the northeast: exactly one to S+SW, at most one to W+N, hence one to NE (and exactly one to W+N, which gives us a bunch of mine-free cells around the 1). I think the inferences that give us the other red and green cells are straightforward.

Then

>! the purple cells are ones whose states we can definitely determine, though I can't tell you what the answer will be. For instance,look at the one "in the corner" at the top. We get that because the green cell to its southwest has only one neighbour; therefore, when we look at it (safe because it's green) we will discover that neighbour's state. Continuing with this sort of reasoning gives us the other purple cells at the top, and the upper of the two purples next to the 5 at the right. The other one next to the 5 is because we know how many mines are around the 5 and there's only one cell left.

After this

>! there will be some other cells we can expand -- e.g., one of those two next to the 5 must be un-mined -- but how many new cells this tells us the state of is not determinable so far as I can tell, and I *think* the number could be zero.

  [1]: https://i.sstatic.net/gIj1K.png