Minmus surface gravity is 0.491 m/s^2; current ion drives thrust with a couple hundred millinewtons, so I don't think a drive could even support itself against that level of gravity let alone with power and a ship attached.
However, we currently design our ion drives for power-to-thrust efficiency and long-term effectiveness. I'm not sure what we could get if we designed them for maximal thrust. Especially since in real life, right now the answer to "Do you want a 'maximal thrust' ion drive?" is pretty much "Well, have you considered using... not an ion drive?", so I'm not sure I've ever seen a treatment of that question based on current tech.
The problem is less our ability to make the drives themselves have a high TWR (thrust to weight ratio) so much as that the power generation necessarily required to run them is very heavy. See here:
However, we currently design our ion drives for power-to-thrust efficiency and long-term effectiveness. I'm not sure what we could get if we designed them for maximal thrust. Especially since in real life, right now the answer to "Do you want a 'maximal thrust' ion drive?" is pretty much "Well, have you considered using... not an ion drive?", so I'm not sure I've ever seen a treatment of that question based on current tech.