What is the ruling on combining prayers in the snow, and what is the scholars' opinion on that, especially Imam Abu Hanifa, and do scholars disavow those who follow an ijtihad that later turns out to be contrary to the Sunnah?

Scholars differed on the ruling of combining prayers due to snow. The Hanafis held that it is impermissible. The Malikis permitted combining only Maghrib and Isha. The Shafi'is permitted combining if the snow melts and wets one's clothes. The Hanbalis permitted it for Maghrib and Isha, and some of them extended it to include the two Dhuhr prayers.

The most preponderant opinion is the permissibility of combining prayers due to snow for whoever intends to go to the mosque for congregational prayer and is harmed by the snow on their way, finding it difficult to reach the mosque.

The evidence for this is the saying of the Prophet, peace and blessings be upon him, alone, for he is infallible, unlike others. The four Imams forbade imitating them if their saying contradicted the Sunnah, and they explicitly stated that their madhhab is to follow the authentic hadith. Therefore, any statement or opinion that contradicts the Sunnah of the Prophet, peace and blessings be upon him, is not permissible to follow.