Is it permissible for a woman to travel alone for work (300 kilometers) if her husband is unable to accompany her, and is the marriage valid if the spouses are far apart?

A woman is not permitted to travel without a mahram, due to the general religious evidences. If she does not find a mahram, and she has an urgent need to work, she may be granted dispensation, based on the opinion of those who permitted a woman to travel with a trustworthy company for a journey of obedience. The presence of both spouses in one place is not a condition for the validity of the marriage. It is permissible for each of them to be in a different country after marriage, but the husband is not allowed to be absent from his wife for more than six months without her permission. It is obligatory to seek advice from trustworthy people before marriage and to perform Istikharah.