For my Shellback Dinghy I was using a 1/4" nylon 3 strand and I had about 3' of galvanized chain on a lightweight Danforth anchor. I was never anchoring overnight, mostly in shallow water off beaches, while swimming , picnicking, off loading camping gear etc.
I have about 110' of the 3 strand and pretty well have never used it all, maybe half.
It seemed to hold well.

Can I use this same rig on my 180lbs. slightly bigger Gartside 130?
I did double the chain length and so far it seems to hold well for the above applications.

It would be nice to have something to feel comfortable anchoring overnight with.
I was contemplating going up to 5/16" line and a heavier Danforth I have, maybe keep a small grapnel handy for a clothesline if needed.

There seems to be a roughly 4.5 m tidal range in my immediate sailing area

Overkill?