I haven't seen an Ivation model that has a continuous drain option on the tank.
Mine actually froze over an inch band across the front, not sure about the internals but it was noticeably heavier when I brought it in the house to thaw.
I also have one of those crystal moisture absorbers in the TT. When the crystals change color, you plug it in elsewhere to have it heat up and release the moisture into the air.
I'm still trying to figure out how I can use my new TT cover and gain access to the DHs. No door zipper! Might put it under the front bed near the outside access panel, propping the bed up with a stud.