Evening Star,
A soft landing on an icy runway with minimum spoiler is not a good idea. A firm landing giving you good contact with the runway with maximum spoiler to dump the lift is much safer. Of course if you land and kick off the drift perfectly then a soft landing is not a problem for directional control, but you do need to stop and for that you need braking action. If you have a cross wind a soft landing on an icy runway could actually be quite dangerous as directional control is lossed.
In fact if the runway is classified as 'icy' you are not allowed to land, according to most countries regulations (I don't know about Russia).