I love my basement sewing room, it is soooo much cooler. With the iron on( its always surprising how much heat accumulates) its just too hot for a upstairs bedroom. Lots of room , plus when I 'm done I just walk away and the rest of the house still looks "normal".
I do run a dehumidifier this time of year. But in the winter I have a space heater that supliments the regular heating system. But beleive it or not the iron being on in the winter ... its not long before its warmed up.