It was in KSPTV (I think the guy's username was akinor, something like that). He landed in a pocket of 2.8% and it took him 3 munar days to get 5 units of ore. Also, you have to manage overheating, which decreases efficiency (an engineer and more solar panels increase efficiency. Resources do not deplete, but overheating and pocket percentage balances this. I would imagine landing in a pocket of +50% would only take in-game hours to fill up the small tanks.