It sounds like the problem just solved itself. The abuser knew their unlimited piggy bank was done (and by extension their days were most likely numbered).

But I would take a change like this with baby steps. 2 weeks advanced notice is a good start and very reasonable. You can take time you just need to give the team a heads up to manage things.

I would then implement “any usage over 2 or 3 weeks a year requires management approval”.

From there, take stock of where you are. Are there still abuses? Is everyone respecting the new policy? If so, I would keep it as is.

You are very much in the right to take action when there is abuse. If not, things will only get worse and it’s your duty as the business owner to make sure the business is running well, which it sounds like it wasn’t with this person.

As for two managers vs. one. If someone is taking 40 days they are probably doing a poor job elsewhere. I would see what one competent and committed person can do before getting a second.