You can expect a racy, possibly unpleasant, high in the end product. I really dislkie unripe weed; it makes me jumpy and agitated and gives me a headache. Your response may be different but that's a common complaint among people who smoke the Beasters, which are by definition taken down 2 weeks or so early.

Is this an issue of hiding the grow while relatives are visiting? This isn't the GREATEST solution, but an extended dark period in a bin hidden in some obscure corner of your home and covered with dirty laundry isn't going to kill your plants, and the stress level will be workable (it's extended LIGHT that's the problem, just be sure to open the bin and ventilate a couple times a day), and then you can finish them properly.
I typically wait until the hairs are 75% browned before I make preparations for harvest- you want to judge harvest time by trichome ripeness; when all the crystals are cloudy/milky, and some are starting to go amber, that's the ideal window.