Q.Chinese lantern over winter
Will my Chinese lantern survive our winter, zone 3 outside in its pot? Is it better to bring the plant indoors during our extremely cold, snowy winters – 20 to 30 degree Celsius below zero?

Your plants should be fine overwintering in pots. You can move to a sheltered location and even a garage for winter will be fine.
You can add a bit of protection around the pot if you like. A bag of leafs is an easy way to do this.
My wintered over pots I add a bit of moisture once a month, Just enough to keep the soil from drying completely and cracking.
https://www.gardeningknowhow.com/ornamental/flowers/chinese-lantern/caring-for-chinese-lanterns.htm