The following test doesn't cover a wide selection of tires so results with different tires could be different but the test parameters are in a controlled environment:
https://www.youtube.com/watch?v=bKtnczk8Mxk
This one talks about 16-17-18 differences:
https://www.youtube.com/watch?v=mhQh3IfXac0
Choice of tires or size can change normal handling characteristics such as turn-in, understeer or oversteer. It is very difficult to achieve balanced handling for any X5. Normal is an understeer. If winter tires increase understeer that's not good IMO. I would much rather it turn better and have to bring the rear back in line than go straight when I am trying to turn.