I read somewhere that with a jammed yoke or elevator it is impossible to fly with the trim wheel because it has no effect being too small to act as an elevator. Can it be possible?
not so, though if it has not jammed in the neutral position that does make it much harder and you would probably need to adjust power to get the nose in a sensible attitude. Not sure how far along your PPL you are, but worth trying it with your instructor holding the cc when you are in the later stage of the course, you will find the way to do things is SLOWLY with very small trim and power changes.
Chute is the best option if you have one and is recommended for aeros.