ACan you make isomalt too early? I want to do a test run before my actual cake yet if I'm successful I don't want to wait expensive isomalt. Is 2 weeks too early?

Whatever you make will need to be placed in an airtight container with desiccant packets NOT TOUCHING the item[s].  This will keep the isomalt in a very good, but not quite freshly made, state.

http://www.amazon.com/dp/B004FC5VT4/?tag=cakecentral-20

I made bottles for my Ice Chest cake about 2 weeks ahead if not more. They were fine but I had the packets stated above bought off Ebay.

You can make isomalt up to a few months early, as long as you store your finished item in an air-tight container with a packet of food-safe desiccant. Don't refrigerate your isomalt creation, because the refrigerator is a humid environment and will cause your decoration to lose its shine and detail.