Will old coffee in the refrigerator keep for 2 days?
If left at room temperature it would certainly become a pool of mold, but if you refrigerate it, especially for just a few days, it should be fine. You would do well to put in a sealed container and probably adding ice to chill it faster would be 'better' but just set in the fridge for 2-3 days (depending on what else is in the fridge) should be ok. 

Beyond that, taste is a personal thing and if you like it that way...go for it.