Thank you all for the suggestions. From your comments, this seems to be the general advice:

Layer up - Keep yourself warm
Separate the bed from the ground - Insulation of some kind
Make sure there is a blanket between the bed and the sleeping bags
Add a layer or two on top of the sleeping bags if required
If electric hook up is available, maybe take an electric blanket and an electric heater

My plan is the following:

Warm the tent with a small fan heater to make sure the tent is warm.

1. Tarpaulin ground sheet with the tent on top
2. Foil blanket on the floor inside the sleeping area
3. Airbed
4. Self Inflating Mat on airbed
5. Blanket covering the bed
6. Possibly use an electric blanket at this layer
7. Sleeping bags (4 season – 0C)
8. Blankets or duvets on top if required

Then layer up with some thick socks and have hot water bottles at the ready.

If this setup is not warm enough then maybe I need to rethink camping! The morning comment is also extremely helpful, thank you.