What is it you want to do?

Generally going to the airport (other than LHR) is not a good idea because even if anyone is there* they are not generally trained in ticketting (especially complex issues) becausr they are contract staff and won't be familiar with the ins and outs of the policies.

* and given there are no flights at the moment there won't be

And if your flight has been cancelled they will refund you. It will just take some time,