I rarely get dew issues with a simple dew shield in place with my refractors (though I just bought Kendrick Premier's for my Tak FSQ for travelling to the COLD dark site), BUT, I had MAJOR dew issues with the Mak I had.
I suggest a dew shield, heater bands, all powered by a thermo-nuclear powerplant.
I hear Fukashima has some spare fuel rods.