(B) No waste/by-products (e.g. filter, brewed coffee granules residue, blah blah) - so much less carbon footprint.

Not sure how you come to this conclusion. The waste is the same (if not more), just ends up somewhere else. Also, you’re adding a whole extra process (freeze drying) requiring extra energy, and water needs to be boiled twice (during brewing and at home).

Lmao why even specify cow milk, any milk is fine. You even mention how you prefer oat milk afterwards 🤯

If you’re not overly concerned with sugar content, try some flavoured milk. I bought some banana flavoured soymilk (Alpro I think) a while ago and put it in the fridge overnight with the oats, was amazing, didn’t even need any added fruits or whatever, though I did add some walnuts I had laying around (after the soaking in the fridge).

I tried overnight oats with yoghurt once and it failed miserably, the oats didn’t absorb anything. Tried it with some milk later and it was perfect.