Removing camellias from pot and planting in ground

A recent thread on here reminded me that I have two camellias - a Japonica and a Cuspidata hybrid in a 50 litre plastic container in the woodland part of my garden. They look healthy, with developing buds and are about 6 or 7 years old.

I am thinking now they would be better planted in the ground in the same place that they are currently. The container is sitting on the soil - quite possibly with tree roots from neighbouring deciduous broadleaves making the ground undiggable. The camellia roots may have already ventured through the container into the soil.

Is it very risky to try to remove and plant out the camellias?
How much root pruning would be needed? Is now the best time of year to do it?

Some days I don't have much strength to lift and shift, due to fluctuating health,which worsens in the winter, so I was thinking of either doing this job in October or before next autumn.

I would probably have to create a raised bank if the tree roots are pronounced.

Help appreciated!