Z4 35is or 335is or M3

I currently drive a 3281cab and I want to step up, visually and engine wise, to another BMW convertible. I do not plan to race the car. I enjoy cruising through mountains and along long, windy roads. I live in Southwestern Ontario where we have moderate winters. I do not want to buy a winter beater. This will be my only car. I love the look of the Z4 but I'm told it's not a winter car. It sits too low. I was told the M3 is also not suitable for winter, even with winter tires, as it's too powerful. It seems like I'm being pointed towards the 335is but I'm not persuaded that it looks sufficiently different from my current car. What are your thoughts?

Signed,
Just a girl who loves a really nice ride with the top down and good music

PS. Are there any other women on Bimmerfest? Let me hear from you as well please.