At least two console generations need to pass

I’d say you shouldn’t have a remaster / remake until at least two hardware generations later. That’s generally the point where the older consoles and their games start becoming harder to acquire. – Powerlord

For remasters, I’d say it’s when playing or obtaining the original is no longer feasible for the average person. For remakes, I’d say at least a generation or two. – Flummoxed Fox

At least two gens. Otherwise, just call it a rerelease. I consider a remake to be taking advantage of advances in technology and gameplay. but in one gen, I am sure it will look nicer, but I’d like to see the refinement of time. – wombat23

I would say at least two console generations should pass before a remake – or at least give enough time for people to think “Wow this doesn’t look as good as I remember it”.

I’d use the absolutely perfect Pokemon Heartgold and Soulsilver as the benchmark, in that was just the right amount of time (10 years) that not only could the magic of the original be maintained, but enough time had passed and the franchise had time to update itself both in hardware and game design that those games felt like so much more than just replaying the old game with nicer graphics. – OnceInAMillenia