Does an elderly person who is unable to perform wudu' perform tayammum?

The Shaykh : An elderly man is unable to stand or move, and there are only his daughters in his house. It is very difficult for him to perform wudu' or go to the bathroom in the house. Is he permitted to perform tayammum for the obligatory or voluntary prayers? What is possible to combine? If it is possible to combine, he performs wudu' and combines the midday prayer with the afternoon prayer, then performs wudu' and combines the night prayer with the sunset prayer, and one wudu' is sufficient for him. This is the case of Salih al-'Ulaqin.