Rav Yaakov Yisroel Kanievsky, the Steipler Gaon zt”l, drank five cups of wine during the seder on Pesach. This was in accordance with the opinion on the Rif who holds that five cups must be drank, with the fifth one being for the fifth expression of geula, Veheiveisi. Although the Rif held that the place for the fifth cup is in Nishmas Kol Chai which we say after Hallel, the Steipler drank this kos during Shulchan Oreich at the seudah.
Other hanhagos of the Steipler were that:
-He only drank wine, even in his old age when it made breathing difficult for him.
– He spent a great deal of time on the floor during bedikas chametz. He once said that bedikas chametz is the hardest mitzvah for him.
– He was Makpid to give out nuts and toasted kernels to all his grandchildren. Even those who did not have the seder with him, he would send to nuts and kernels to their homes.
– He did not eat gebrochts but allowed his family to do so. Because of this, his meals were prepared in special keilim separate from the rest of the family’s keilim. In his old age, when it was hard for him to eat matzoh unless it was soaked in water, he was matir neder and ate gebrochts as well. (Toldos Yaakov)