I can only talk about my GS300 but with winter tires I would expect both to be fine. I used Artic Alpins on my GS and never had a single problem here in Illinois. I now have an '04 LS430 that will get winter tires put on it and expect to get the same mobility.
2009 Ford F-150 King Ranch
2004 Lexus LS430 Custom Lux w/Smart Access - SOLD in 2009
2005 Honda Odyssey Touring R&N
2001 Acura MDX Touring Navigation - SOLD in 2005
1998 Lexus GS300 - SOLD in 2004