I like something in the 40 - 45 watt range. You don't necessarily need that much just to join wires to terminals. But, if you try to solder something, like a braid, to the back of a pot, you need something that can get the pot up to temp quickly. You can actually do more damage with an undersize soldering iron because you have to hold the iron on a part for a longer time.
I think you'll do fine. If not enough, plug it on 240.
Exactly you need to lay down enough heat locally and quickly before it spreads out and melts everything else. Like HB wax potting...... (facepalm)40 watts works so much better for soldering to the control pots.