بسم الله الرحمن الرحيم
It is good for you that you offer witr salah after offering sunnah of Isha salah, and then offer only tahajjud in last night so that you have not to do qaza of witr. However, if it is missed sometimes you may offer its qaza in daytime.
Allah knows Best!
Darul Uloom Deoband
This answer was collected from the official ifta website of Darul Uloom Deoband in India.