There is a plugin called Bulk Resize Media that might be able to do this for you, but I am not sure I would recommend doing that.
Bulk resizing images to a SMALLER size is hardly ever a problem. Images are easily compressed without degradation. They are compressed by removing every Nth pixel, which the human eye rarely notices. (I know, greatly over simplified)
Making images LARGER, by contrast, requires “best guess” technology to replace the missing pixels with various calculations, based on the next closest pixels. (again… greatly over simplified) This usually results is severely degraded image quality.
I would only recommend using this plugin if you have no other choice. It would be better to modify the theme (or create a Child theme) to accept your existing images, and only display NEW images at the higher resolution.