I am a third year beekeeper and have done the 1:1 both ways. If going with the unheated water, I put it into a large clean plastic container with the sugar and shake it a lot. As long as your quantity is small enough for the bees to consume it in a day or two this works pretty well. I have had the sugar in unheated syrup sink to the bottom of a hive top box feeder when the shaking was insufficient and it was one more thing to clean out.
This year I am only feeding a nuc with a quart jar so I am heating the water - I don't necessarily boil it -- just heat it hot enough so that the syrup is clear and not cloudy -- i.e. the sugar has melted. Heating this little bit is convenient so I figure why not.
In the fall, however, with a 2:1 mix, you pretty much have to heat/boil it to get it blended.