Great conversation.
True, the important thing to do is sleep in one of your four best directions, this means that when you are lying down the crown of your head is pointing in one of your four best directions. In addition to this the other priority is to be sure you are in a position of power in relation to the door. This means that you are able to see any incoming traffic without being in the direct flow of the door.
There is definitely no such thing as perfect feng shui and we all work with what we have. Marie has also mentioned that if there are no other options for moving the bed you can experiement with angling yourself in bed so that at least the crown of your head is pointing in one of your ideal directions. Marie states that she has used this little trick when traveling and in hotels.
All the best,
Kat