Wondering if the extra amount of fluid needed between hot and cold could be simulated by tilting the car when filling cold?

Perhaps the difference is too great, but don't like the idea of being under the car when running. I don't have the most secure footing for jack stands.

Does someone know the amount extra?

2000 XK8 Coupe

 

Ideally you should try and get access to a ramp or better hard standing. When I filled mine, I deliberately overfilled it because I knew a bit would flow back out whilst I was refitting the fill plug.