It's been a bit since I've done it and I don't have it in front of me to describe it accurately but I do believe there's a time slider bar you can move it to the winter months.
Life_feeds is correct, there's a time bar slider as an option in one of the layers if I remember correctly, but the images it gives you are completely dependent on when the satellite going overhead took them - there are some pretty large gaps in time and it might even skip seasons or a couple years in between. Even with that being the case though, you should be able to get something with all the leaves off in the area you're checking out.