Likely doesn't matter, but in my old house, I used hot water straight from our utility sink. I had a 150+ foot run of hose out to the rink though so tended to cool off some by the time it got there.
Only drawback to really hot water was that you needed to keep the hose moving. Any excess hose lying on the ice with all of that hot water running through it will melt down into the surface of your ice as you resurface so try not to let excess lengths/coils of hose lie on top of your ice for any length of time.
I do like to use hot water though as it tends to melt down the high points and fill in the low points and seems to create stronger ice (my opinion only). I have side by side outdoor spigots now and currently use ~ 1/3 cold and 2/3 hot, but fill into a large sprayer tank on my garden tractor and use that to resurface so don't have all that hose lying around anymore.
Oh, and unless you have a tankless/in-line water heater make sure your wife gets her shower in before you resurface too, trust me, otherwise makes for a rather chilly reception once you head back indoors.... :-)