What should I wear for New Years in Reno?

OK so I'm going to visit my guy in California next week and we're going to be Reno for New Years. I'm sure we'll be going to bars and such, but then he said we'll be going outside to watch fireworks. It's so hard to find a cute dressy outfit that is suitable for the cold weather. It's going to be cold there. I have 2 very very cute shirts that I bought last year and didn't wear. They are both dressy black and silver halter tops. I was going to wear them with either really dark denim jeans or gray/silver dress pants.The only problem is, it will be cold there. Is it stupid to dress in a halter top? I've been trying to find something to wear over them (like a black blazer) but nothing looks good with it. I have a nice Black coat I can bring, I just know I won't want to cart it around all night. Do girls dress in tops like that even though it's cold? If not, Any suggestions on what I could put over my tops or if I should just find another outfit?