For anyone that is interested, I successfully cleaned the engine bay and surrounding area using a spray degressent.
I left the degressent to work over about 20 mins, then jet washed all around the engine and oil pan underneath the car. I turned the wheels to gain access to the underside of the car.
I also removed the soundproof board from under the hood of the car and jetwashed it too as this was soaked in oil!

After the wash I started the car and took it for a good drive - everything was perfect!
No smell, no burning - very happy!

Thanks again.

BTW:- My local BMW dealer quoted me €400 ($550) to clean the oil from the engine bay!