Go with b and cancel right after you get your visa. You might also want to call the hotel directly and ask them to add your name to a booking/remark that there will be 2 people staying. I don't think hotel will have any issue with 2 people staying in a room booked for one, but they would need to register both of you with the local authorities and that's when hotel check-in agents may give you some grief if you have only 1 person on the reservation.