Is it permissible for a traveler to shorten and combine prayers if the duration of his travel is one month, subject to increase or decrease?

We issue a fatwa that if a traveler intends to stay in a place for four days or more, he is considered a resident from the first day, and is not permitted to avail himself of the concessions of travel. Rather, he must offer the prayers in full and fast Ramadan. However, if he does not intend to stay for that duration, he remains eligible for the concessions of travel, such as shortening and combining prayers.