IB's only need flat perches and protection from the wind even in the northern parts of the US. Higher Spauldings and Greens are normally kept in a heated coop. We use an insulated and heated coop for our high Spauldings.
I DO NOT RECCOMEND heat tapes. I have seen them be faulty and then there is the question of installation. Make sure the thermostat is in contact with the perch and is covered by the carpet if you try them.
I think you saw my 'Special Needs' pen when you were here, Peggy only has two short legs with no feet and Skippy only has one leg with a foot, short toes, and the other leg is half gone with no foot. They both do fine in deep fine sand and heated coop. They must be kept in sanitary conditions...
That is called the twisted tibia, think of the leg bone comes out of the hip socket. The ligaments that should hold the bone in the socket have been damaged and without surgery, it can not be fixed.
Actually, I am quite impressed. I find that the wire brooders tend to break a lot of toes and then we find them after the period that I thought they could be fixed. I had always thought that I would have to re-break the bones to correct.