A UK Examiner (not an Instructor) can assess you as Level 6 (fluent): 5-10 minutes face-to-face. If you are not Level 6 then you would need to be tested by an approved Language School.
You could try Weston (Dublin). I know a UK Instructor, who I think is also an Examiner, moved there about a year ago. Alternatively take a trip North of the border.