Is it permissible for a man to have intercourse with his wife if she is in a state of janabah and unable to perform ghusl due to illness?

It is permissible for a husband to have intercourse with his wife who is unable to perform ghusl, regardless of whether she was previously in a state of janabah or not, and regardless of whether the cause of janabah was intercourse, the cessation of menstruation, or postpartum bleeding.