128 GB or 256 GB MacBook Air w/ windows question

I'm thinking about buying MBA and I'm not sure if down the road if I'll need windows for school. For cost reasons I was gonna get the 128 gb option but got to thinking if I use boot camp to run windows will I be too low on gb space?? Should I just spring for the 256? If anyone is my situation help me out!

Besides iWork and photos I don't know what other programs I'll be using. I can use iTunes Match and streaming to save space too. Thanks.