Has to be soil not hydroponics. Hydroponics with just water and no added nutrients just simply will not work, and you'll know that nearly immediately so the only time you waste would be the initial startup. With soil it'll survive just fine for a long time, perhaps even the whole way through if the proper procedures are followed. Its just a matter of what the end result will be.

Not sure if this has been mentioned yet but I suppose this is a very important piece of info to know. Plants need light to break down any and all nutrients they uptake in order to actually use them for positive growth. It is important to find a balance in the amount of nutrients you provide the plant and the amount of light it receives. So when using a less than average light source, your plant will use less than average amounts of nutrients, so it will take longer for the plant to thoroughly use up the organic and nutrient content of the soil itself thus allowing for further delayed addition of nutrient solutions to your soil, and additions in smaller quantities.