بسم الله الرحمن الرحيم
(1) If the mosque is in good condition then avoid demolishing it. You should look for other ways to make arrangements for Jumuah and Ramadan.
(2) You should avoid demolishing the entire mosque for new construction or expansion, rather when it is necessary you should demolish it in parts one by one and construct it side by side. In case the entire mosque is demolished the salah shall be stopped which is wrong.
Allah knows Best!
Darul Uloom Deoband