Section 8?

Possession - Section 8 and Section 21

We have a possession order (via a section 21) for a property we have been trying to get back for 18 months because we eventually need to sell the house but befire that my husband needs to live in it temporarily while he has chemotherapy for his leukaemia. The tenant hasn't moved out by the date of the order, so we're going to have to go down the route of bailiffs. But because of the eviction ban we don't know when that will be, currently the ban is until 31st March, but we don't know if that will be extended. As from 1st March, the tenant will be 6 months in arrears. We were wondering if we should issue a section 8 giving 4 weeks notice (based on 6 months arrears) in the hope that the whole process may be quicker (as it will be exempt from the bailiff ban) than waiting for the eviction ban to be lifted and evicting him using the possession order we already have?