2007 Tahoe doesn't want to start if it's below 60 degrees

My '07 Tahoe doesn't want to start if it's below about 60 degrees. Starts just fine when it's warm outside, but it definitely seems to be only when it's cold that I have to try more than once. It has a new battery and new alternator, and I had those tested and they're fine. Also will not remote start (just clicks) in the cold. Any ideas for the mechanically challenged?