Yes, there is nothing wrong with delaying saa’i after tawaaf, although it is better to do saa’i straight after tawaaf.
Ibn Qudaamah (may Allaah have mercy on him) said in al-Mughni (10/240):
It is not obligatory to do saa’i immediately after tawaaf.
Imam Ahmad said: There is nothing wrong with delaying saa’i until one has rested or until evening.
‘Ata’ and al-Hasan did not see anything wrong with the one who had circumambulated the Ka'bah at the beginning of the day delaying al-Safa and al-Marwah until evening. This was done by al-Qaasim and Sa’eed ibn Jubayr. End quote.
It says in Fataawa al-Lajnah al-Daa’imah:
The Sunnah is that saa’i should be connected to tawaaf as much as possible, but if one delays saa’i a great deal and then does it, that is valid.
And Allaah is the Source of strength. May Allaah send blessings and peace upon our Prophet Muhammad and his family and companions. End quote.
Standing Committee for Academic Research and Issuing Fatwas
Shaykh ‘Abd al-‘Azeez ibn Baaz, Shaykh ‘Abd al-Razzaaq ‘Afeefi, Shaykh ‘Abd-Allaah ibn Qa’ood.
Fataawa al-Lajnah al-Daa’imah li’l-Buhooth al-‘Ilmiyyah wa’l-Ifta (11/263)
Shaykh Ibn ‘Uthaymeen (may Allaah have mercy on him) said:
It is not essential that tawaaf and saa’i be done one after the other, even if there is no reason for that, so if a person does tawaaf at the beginning of the day and saa’i at the end, there is nothing wrong with that, or if he does tawaaf at the beginning of the night and saa’i during the day, there is nothing wrong with that, because doing tawaaf and saa’i one after the other is Sunnah, not obligatory. End quote.
Majmoo’ Fataawa Ibn ‘Uthaymeen (23/201).