Yes, I think there`s diffrenece between them, but it`s not so big actually!
![Smile [:)]](/emoticons/emotion-1.gif)
) In my opinion you can say "the winter" if you are talking of a particular situation, but if you`re saying that in general, you don`t need to say "the". For example:
1) I`ll go to my grandparents` in the winter ( it means this winter or may be the listener knows what time you will go there exactly)
2) I like to go to my grandparents` in winter ( in general, you like to go there in winter seasons)
This was my opinion,and I hope you`ll find it useful!