Wet is a bigger killer than cold and they stand being dry for ages, so as long as it doesn't freeze and the compost doesn't get more than just occasionally damp they could survive outside as long as you keep the rain off in a very sheltered spot.. I've even got away with this in a mild winter at the foot of a south wall but counted myself lucky and we're milder here than you are.
If you have a suitable window in a garage or shed or even a spare room you can just move the trough there as it is and let it become pretty dry.. This would be safer in Cheshire as it does freeze sometimes.

August is a good time to take geranium cuttings so I'd do that as well and keep them somewhere light and warmer. When you cut them leave them for a short while for the ends of the stems to dry before you plant them and they will probably root best in a dry or dryish open gritty soil.They would rot in wet compost. They are actually well on the way to being succulents and like similar treatment. Reducing the top growth should help overwintering too. You can let them lose most of their leaves if they are in a pretty cold place..

Yours look as though they have been watered quite a lot so towards the end of September gradually reduce the water to harden them off.

sorry bout not getting back to you sooner,but thank you very much for your advice,however,no way can I move the rough,weighs a ton,will try to keep it protected during the window,perhaps some plastic with ventilation holes and some wooden sticks,if you understand me.Do you think that will be ok,by the way,it is on bricks,so not touching the ground.

I would move the plants into individual pots and overwinter them that way. Whether your idea would work depends so much on what sort of winter we have and we can't predict that. On a south facing wall in a mild winter andoutof the rain they'd possibly survive but its risky. They would survive on a windowsill in an unused bedroom or garage windowsill if you have nowhere to keep them growing on and would need only the minimum of watering. You'd get the majority of the leaves falling, which is good as it reduces the plants needs. Then in spring bring them somewhere warmer - perhaps a kitchen windowsill etc for a few weeks until the weather warms up enough . Just remember the colder the weather the less you must water. They are semi succulent plants so that gives us a clue to their needs.

As i said the best thing in these circumstances another year is to take cuttings in August, and they will be in small enough pots to bring indoors over winter.

Where I live we tend to have quite mild winters,the area is sheltered by the Pennines,rest of country can be covered with snow..here..nothing.so I might get away with covering like I said, we shall see😏

Don't let them get wet when its very cold then.