Answer
(Fatwa: 1486/1173/L=1430)
It is better to perform sajdah instantly after reciting the verse, delaying is makrooh as one may forget it altogether.
(2) In this case, he will have to perform two sajdah, one sajdah will not suffice.
(3) It is better if you make wudhu and perform sajdah, otherwise it is mustahab to recite سمعنا واطعنا غفرانک ربنا والیک المصیر and perform sajdah later when feel easy:
في التتارخانیۃ: یستحب للتالي أو السامع إذا لم یمکنہ السجود أن یقول: سمعنا وأطعنا غفرانک ربنا وإلیک المصیر (الشامي 2:583)
Allah (Subhana Wa Ta’ala) knows Best
Darul Ifta,
Darul Uloom Deoband