This mod gives multiple options for extending the duration of Invisibility and Greater Invisibility, extending them from 10 turns up to an entire Long Rest. The Long Rest versions even have the option of turning off Concentration if you absolutely want to break the game, although I will not be able to fix any potential scene problems with being invisible. I've kept the Invisibility and Greater Invisibility files separate so that you can change the duration of both or make them different lengths.

I personally will only be using the Invisibility 100 turns mod as that is how the spell is used in D&D 5e, but I threw in other options so you can play how you want. This will most likely not affect any items that make you invisible, though that is a goal for the future.

I installed this mod using Baldur's Gate 3 Mod Manager: https://github.com/LaughingLeader/BG3ModManager
In order to install this mod using BG3MM: (Must install Full Release Mod Fixer first, following their install instructions)

1. Download the mod manually
2. Extract the mod to whichever folder you'd like
3. Place the .pak file into your BG3 Mods folder, located by typing %appdata%
into your search bar then going to /Local/Larian Studios/Baldur's Gate
3/ Mods
4. Open up BG3MM and if you don't see the mod on the right side under Inactive Mods, hit the refresh button right above it (if it's
still not there the .pak file is in the wrong place)
5. Drag the mod from the Inactive Mods (right) side to the Active Mods (left) side
6. Click File and Export Order to Game (Ctrl + E)
7. Play Game

If you need it, there are pictures up top after the mod pictures that show where these things are.

If you're downloading with Vortex Mod Manager, I haven't tested it but
I've heard you can click Download With Manager instead of Download
Manually and the file should work. I'll try troubleshooting that once
the files uploaded.