The questioner says: If the period for wiping over the socks comes to an end, does one’s taharah (wudhu) become invalid?
If the period of wiping comes to end, it doesn’t nullify taharah (wudhu). All it means is that the concession for wiping has come to end, but he continues to remain in a state of purification until he nullifies it.
Shaykh Muhammad ibn Hizaam – may Allaah preserve him
Abu Yusuf Abdulfattaah