I think it's a good idea to travel light, especially since you're planning to travel before your study abroad program begins.
My daughter studied in the U.K. for 5 months last year and she took a 23" roller suitcase and a small duffle bag ( carry-on) where she packed her laptop, coat, gloves, scarf, hat, & a change of clothes (just in case her suitcase didn't arrive at the airport)
My daughter basically packed as though she were going away for a week. I don't recall the exact number of clothes but it was a minimal wardrobe which included something like this: 2 jeans, 4 thick leggings, 2 long underwear bottoms, 6-8 tops (short & long sleeves) 2 long sleeve thermal tops, 1-2 sweaters, 8 pairs of wool socks, underwear, one fleece vest, hat, gloves, scarf, one hooded, waterproof down coat & one short waterproof down jacket.
She wore her hiking boots on the plane & packed another pair of shoes in her suitcase.
Most of the other students she met had packed BIG roller suitcases and she was glad that she could handle her own stuff.
In retrospect, she thought the duffle bag was a bit of a nuisance, so a backpack would have been better. She did take a small backpack but not big enough to fit everything that was packed in the duffle bag. Her winter coat was the bulkiest item she packed (as well as her waterproof hiking boots worn on the plane).
Enjoy your study abroad experience!
Edited to add...
She did end up buying a few clothes there as well as a pair of knee length waterproof leather boots, and a pair of Vans, once the weather changed.
When I picked her up at the end of her studies, we had to send a package home which included most of the winter clothes, both pairs of boots & some souvenirs, prior to our 3 week trip :-)