You've brought up a very good point in this comment. Icarex and RipStop Nylon (RSN) are two similar yet very different materials. The key difference for this conversation being water absorbency. Icarex is by design pretty resilient and it absorbs very little moisture. RSN however varies widely due to age, coatings etc. Depending on those factors to a degree, RSN WILL absorb water and get heavy quickly.. Knowing that RSN will get soaked, I can think of one scenario that if you carry a water drenched Nylon kite out in sub freezing temps, let it freeze and fly it frozen, the frozen water crystals in the fabric would be sharp and could cause accelerated wear/failure. This is a very specific set of circumstances that most people would avoid anyway out of common sense but it does highlight the specific differences in the fabric itself.
If you are flying in 40 below, Have fun and good luck. (Fun Fact, 40 Below is the one temp the Celsius = Fahrenheit. ( -40C = -40F ))