G35 vs 350z
I shopped both and chose the G35 for the following reasons:
1-G35 is way more roomy inside and that is important for me for daily driving- I'm a big guy.
2-While I wasn't worried about back seats originally, they've turned out to be great, I can bring friends, fully recline my seat for a nap on ling drives and put my briefcase, coat & other stuff in the back seat.
3-G is more expensive because it's a higher-end car than the z. It's considered a luxury sports coupe and the Z is a pure sports car.
4-G is easier to get in and out of because the doors are bigger. This may not mean anything to you but again I'm a big guy and after a few years, stuff like that begins to matter on a daily driver.
As for the weather, I don't see any advantages the G would have over the Z. Same chassis. Either car is a great choice. You might consider a 300Z as well. A well built TT 300Z is a badass machine, very roomy inside, unique, has TTops, more aggressive looking, hatch-back and overall one of the best sports cars ever made. I like them better than the 350. The 350 is going to be a more reliable machine, it just depends on your budget and if you have a great Z shop close to you.