The time of witr ends with the athan of Fajr. The rest can be performed between Athan and Iqama but one should combine intentions. For example, he should pray the Sunnah of Fajr with the intention of wudhu and tahiatul masjid at the same time.

Can we perform tahiyyatul wudhoo/masjid (or make up our witr if we couldn’t squeeze it in before Fajr beginning time?) between the adhaan and iqaamah of Fajr salaah?