20km sounds a bit out of range of its habitat This snake has memory of all of its warm spots, water supplies, places to find food. You may as well cut off its head and wear it as a pendant if you take it 20km and drop it in the middle of nowhere during winter.
There have been hints and rumours of permits for common colubrid snake pets (i.e corn snakes, rat snakes, king snakes etc) to be done away with and no longer compulsory in the cape provinces. Can anyone offer additional info?