If you've got enough for 2 weeks, you can survive 2 months! Just ensure you can deal with cold / wet - that's what takes the case space. If you get bored, buy a few tops - they don't cost that much, and won't take too much space. Don't pack books unless you have to, or large quantities of shampoo etc. They sell these things in most places. Even if you have to try out new brands, it will be fun.