Suggestions for best mode of transport from Paris to Beauvais Airport (approx. 80 km north of Paris)
Bus.
Tim, you may be confusing the Beauvais shuttle with the Roissy Bus to CDG (which runs from Opera). The OP wants to head to Hotel Concorde Lafayette area (per your link, so I am guessing you misspoke). The bus is about a two block walk from the metro.
Take the airport shuttle bus from Opera to Beauvais. Be at Opera 3hr15min before your flight's scheduled departure time. See here.
You are right, Michael. I meant to say Porte Maillot, but I typed Opera. My brain knew better, but my fingers didn't.