When one wakes up late and has very small time or no time at all to eat for suhoor according to the current masjid timings they follow، Is it possible for them to follow another masjid which has a later fajr time so that can eat suhoor?
Fasting start time is not pegged with certain Masjid’s time table. Instead, Allah has stipulated the start time to be Subh Sadiq. In our experience and research thus far, Subh Sadiq corresponds with the calculations when sun goes 18° below the horizon. Our Salah times at ilmHub & Darul Iftaa strictly follow 18° calculation for fajr. This will continue until we do our own observation to establish another opinion, or receive an equally viable research to the contrary.
Keeping the above information in mind, one should stop eating suhoor before the times on our calendar. If one gets delayed, then the only buffer time is 5 minutes (imsaak), which we indicate on our table. Beyond this time, one would have eaten within the Fajr time invalidating their fast.