It really all just boils down to what you're comfortable with and what suits your personality. What ***** is that you're having a hard time getting to test drive the Viper to see if it fits the bill. Maybe some generous owner of a new one in your area might be nice enough to offer you a ride in theirs? From what I've read so far I'd say it seems like the Porsche would probably be the better fit for you, but I think it might be a little bland and lack some personality. A Viper might not be the fastest car on the road, but when you drive one you certainly feel like it is. It's just a different experience from a lot of other performance cars.
Personally, I daily drive my stock gen 3 rain or shine nearly year round and don't mind one bit. If it snows I'll leave it in the garage, but as soon as the snow is off the roads I'm back on them. The car is almost entirely composite, aluminum, stainless, and highly coated and corrosion resistant steel (frame is galvanized and e-coated from what I understand). I wash it generally every weekend or two as well, so whatever salt might linger is usually rinsed off farily quick. 10k miles in 7 months of ownership and it looks and drives the same as the day I bought it (minus some extra wear on the front fascia). People think I'm crazy, but it just doesn't bother me driving it in all conditions. I've had it in torrential rain more than once and it's never given me any trouble. I've driven it in 20 degree weather without any issues either. About the only thing I ever carry in the car is myself to work, so storage space is a non issue. Even on a weekend trip I'll just throw a duffle bag in the trunk with a change of clothes and I'm good to go. I think the car is plenty comfortable and easy to drive. Getting in and out is a little different compared to other cars, but not a deal breaker by any means for me. Everyone is different and will have different tastes and requirement in their cars. Some of us are lucky enough to be able to have a few different ones for different occasions. Others make due with just one. Find what stirs your passion and have fun with it, whatever it may be. The only one who can decide what car is the right one is you.
What tires are on your car that you drove it in 20 degree weather? That's pretty much as cold as it gets here.