Is it permissible to wipe over the socks for the 'Isha prayer if the preceding ablution for the Fajr prayer was separated from it by a tayammum due to the unavailability of water during the day?

It is permissible to wipe over the two socks if the conditions for permissibility are met. The duration for wiping is one day and one night for a resident, and three days and nights for a traveler. A man performing tayammum due to the absence of water does not affect the concession of wiping, nor does it invalidate it.