Changing media resolution for older images

Hello.
I have a quick question that I have not been able to find answer to:
Problem is that I have thousands of images on my blog:
https://www.aurelm.com

That have been set up to resize to a certain size (mostly 950 on highres size horizontal). They looked fine in my old theme but on other themes the size of the blog body is bigger so they look very small and out of style. I need to resize the images to something bigger, however if I do this using regenerate thumbnails or something it does not change the names inside the posts that are something like this:
https://www.aurelm.com/wp-content/uploads/highres-Netherlands-sheeps-01-950×633.jpg
with the new names.
Is there any solution to totally convert the image sizes and also update the posts with the new ones ?

Thank you
-Aurel