بسم الله الرحمن الرحيم
Perhaps Gorakhpur is yours as well as your parents’ native place. If it is so then as soon as you enter in Gorakhpur city you will remain no longer a musafir and you will offer full salah. No matter you go there only for one month or ten days or less than it, in each case you will not offer qasr salah there rather you will offer full salah. This is the ruling pertaining to native place.
Allah knows Best!
Darul Uloom Deoband
This answer was collected from the official ifta website of Darul Uloom Deoband in India.