If if gets to taxes/fee page,.NH qty thru Aeroplan is pretty reliable. Not sure if it will let you get that far without enough points ..

If you have an sxpertflyer.com account, you can see the seat map. Likely one seat marked unavail on NH is actually blocked from pre-asspre-assignment, which EF could confirm

or.... post the flight # and date to that forum link in the reply above. Someone on FT will check avail for you if lucky (or.... book the award flight out from under you if unlucky )