If you pass the Manual UK test, you can get in a Manual or auto car and drive
if you pass in an AUTO car, you are restricted to an Auto Cars till you "pass" a Manual car test
Which isn't going to be hard, since passing an Auto test, you have road awarenesss (hopefully) and control of a car
Adding a clutch in after a little practive will give you much better control - esp in the snow
Ziggy