You could use fans to blow on the fermenter and try to evaporate the condensation, although if you are blowing humid air it might not work very well. What you really need is more insulation so that the inside is cold but the outside of the insulation doesn't cool below the dew point. A conical is an awkward shape to insulate, but you should be able to come up with something that would add to the insulating value of the neoprene. Look at bubble wrap, insulation batts, blown foam or some combination of those.