Extreeme Danger...............
You don't need an IR to fly into Heathrow.
If you could find a very quiet time (late at night) to fly in you could probably arrange it.Christmas day used to be a favourite.
You would need to telephone Heathrow OP's for a handling agent and general permission (AND COSTS), then Heathrow approach at West Drayton to find out what they want you to do.
Regards
FBW