That’s a tough one I’m afraid. Unfortunately I don’t have any good ideas either.

I used to have the same problem but it was possums rather than stray cats. I even moved my cat’s dry food and put it on my spare pillow on my bed each night (I live alone lol) but one night I woke to a possum in bed with me, eating the biscuits anyway.

Now my cat is strictly an indoor cat (as he has lost an eye) and I don’t have the problems anymore.

Sorry I know that doesn’t help you at all. Good luck.