suitcase

I’m travelling next January/ February to Europe for about 25 days and I dont know what to do regarding packing. I have a large suitcase (which is a bit heavy when is full) and Im having doubts about it since I’ll be taking trains from city to city. Then, the backpack, which is smaller and easier to carry on trains, seems the best option. Well, the problem is that I’ll be travelling in winter and Im not sure to use a backpack because I’ll be packing winter clothes, which are heavier than summer clothes, and Im rather small to carry a lot of weight on my back… so this is a big dilemma.