Another option would be to get any bags up the northern end of the Met Line, say Rickmansworth. Get the tube north out of Wembley Park (will the less busy direction). Trains run every 15mins and take around 30mins. From Ricky in a cab (£40 ish) you're 3 mins from the M25 and with a clear run 25mins to Heathrow.

Another option would be Uxbridge - the tube journey would be a bit slower as there are more stops, but you're closer to the airport and a taxi has the easy option of local roads via Yiewsley or M25 to get to the airport depending on traffic conditions.