I tried, 1600x900, the picture seems clear and sharp. But it seemed a tad too tiny. Then I tried 1280x720, it wasnt tiny anymore, but its very blocky and not so clear.
Install Widescreen with a lower resolution maintaining the same ratio, 16 / 9, I assume (you probably meant 2560, not 250). For instance 1600x900. If you set the game in full screen mode, usually the monitor will expand to the full size and you'll get the upscaling done by the monitor or the graphic card. There is no way to only expand the UI parts while maintaining to area view with the full size.
Yes sorry i meant 2560x1440. And i will try what you suggested thanks.