How far do bees travel on cleansing flights?

[greenbtree]

So out of my five hives, one has survived the Winter so far.  That one was down in a dell on my property.  I have noticed that it is far less windy there, and on calm, sunny days it is warmer.  I have some package bees coming and am thinking of putting all my bees down there.  How far do bees travel on Winter cleansing flights?  Anyone know?  Lots of Nosema in the hives I lost - lots of other folk in northern Iowa in the same boat apparently.  I was worried last Fall because snow gets deeper there, but I built hive stands over the Winter and am adding top entrances to my hives.

JC