How do I manage my rooms files

Hi, I'm working on a rogue-like game, the level is generated procedurally each floor is composed of 8 rooms. Theses rooms are generated from an array load from a JSON file.

I hesitate between:

-creating a file for each room. (I think the project may be really heavy)

-making one file for all rooms by creating an array of c2array in my JSON file. Then each room would had an ID and I would call them by their ID. (but i'm not sure how to can I make it)

What do you think is the best option?

When you said "heavy", how many Megabytes are we talking about here? Are they actually negligible by modern system?

I'd say stick to the method you are most comfortable with until it no longer works.