Yes zucchini spaghetti can be frozen and kept for up to 12 months in the freezer.
To thaw the zucchini spaghetti just boil it.
Fill a pot with some water and add the zucchini spaghetti to it and then boil the water and zucchini spaghetti which will thaw it out.
You should place the zucchini spaghetti in a sealed freezer safe container and you should eat it within 6 months for the best taste and freshness.
Although the zucchini spaghetti will keep for a year or longer but it loses it's freshness the longer it stays in the freezer.