Relinking images after domain / provider transfer

I searched for this in the archives and found a few thread (years old) about it, but nothing really seems to be an effective way to do this. I don’t know if recently something new has come up to fix this issue.

As stated in the title I just moved providers. I exported my blog with the export function and just imported the blog to the new server. I checked the box for the missing media, but it only imported the posts, and failed to import the images.

Now I have 5,5 years worth of blog posts with missing links to images.
I have all the images still, but -of course- the folder structure is no longer the same for the images, and I’m talking thousands of pictures that would have to go in specific subfolders with the right dates and all that kind of laborious, time consuming work if it had to be done manually.

Is there a way to relink the images to one single folder (called, say… “old”)?

[Please don’t bump]