Edit: sun will never set/living in 24 hour sunlight. The fasting time is during daylight hours.
The most misunderstood part about Islam is that how practical the religion is - Islam expects believers to give it their best shot, within reason and without being judged by some rigid binary rule.
It's perfectly okay to not fast for 22 hours and it's also okay if you can make it. Islam prioritizes health and well being.