If he's introverted I strongly suspect that the uncertainty in his messages is because he doesn't want to suggest something that you're not happy with, hence why he gave you an out in the form of the weather being cold. And as it happens, you did take that out and rearranged the date. Which is ironic, because I expect you were both sat and home really want to meet each other, but both being too insecure to commit to it in case the other one didn't want to, and the end result was that nothing happened.
Stop over thinking this and just meet with up with him, regardless of the weather. You'll find out so much more that way rather than second guessing entirely innocuous texts.