As others have mentioned, I'm trying to increase the number of save files from 5 and also to save wherever I want. 
Milf's Resort_Data (folder) -> Managed (folder) -> System.Configuration.dll
I can't personally edit that file (on Unity or notepad++). I'm assuming it is that file that needs altering. 
I don't want to pay on Patreon. 
Can you (the person who made the game) not sell the file on eBay or something?  
Also, I don't mind paying for the game. 
I would prefer it on a platform like steam (doesn't have to be steam though) - a one off purchase. 
It would just make things so much simpler.