You can do it with this awesome script:
I am using 800x600 resolution in my project, and I can see around 24-26 tiles horizontally and around 18-20 vertically (not sure, never checked it actually, but I can see much more tiles than with the default maximum resolution, which is 640x480).
The script itself wont change your resolution, you need to do that yourself.
If I remember right, the code looks like "Graphics.resize(x, y)" or something similar.
You can also use any other custom script where you can edit your game resolution (Yanfly's Core Engine script, for example), just make sure that the unlimited resolution script is above every other custom script.
Be advised thou, the size of the resolution will affect your FPS rate. Use an anti-lag script to avoid it as much as you can. I recommend Moghunter's anti lag script, because you can set what will your game refresh on the map measured by the distance from your actor on the screen. This includes events as well, so a warning: in certain conditions, some off-screen events can stop functioning. But if you know proper eventing, this will not be an issue. But if, by any chance, you are using Mirror movement script from TDS, make sure to not move any event out of the screen that is actually mirroring the player's movement, or your game will crash. So far, that is the only issue I encountered, and fixing it took me a few minutes only.
Okay, have fun with your new resolution and your new range for the area of view!