Rusty_Hinge writes

Unless the apple tree is diseased with something like canker, I'd trim
off the dead wood and see what happens - apple trees are notoriously
tenacious of life.

I know of several trees which have blown right over, and despite having
around a quarter of their roots left in the soil, were bearing good
crops two years later.

Just paint over the cut ends with a suitable wax. I use the wax that
cheeses are covered in - it's durable and pliable.

Agreed. Our elderly Bramley was blown over in the 1987 storm. We assumed
it was a goner, and it was blocking the whole width of our very small
garden, so we trimmed off all the branches. We never got around to
dealing with the now-horizontal trunk, and next spring it produced
masses of new shoots.
--
Kay