Leave it until march then cut it right down to the ground. A bit of scrunched up fleece or bubble wrap shoved in the middle will give it a little frost protection.

SD Hello I have pruned all my fuchsias back apart from Purple Pride and Mandarin Cream and they are like yours so many flowers still.

And these are not hardy fuchsias.

I always need to give frost protection and last yr I did and still lost all my fuchsias except my hardy standard which is in its 2nd yrs growth.

The fuchsias I pruned are now giving new growth again.

Agree with Badfish, don't cut it at all till it shows signs of growth next Spring. A word of warning though - hardy fuchsias are frost sensitive through their roots, so any in pots, in very cold temperatures, may be killed. You could move the pot up against the house wall, in a sheltered, warmer spot, or bury the pot in the ground until spring, or insulate the pot in some way to give added protection to the roots.

I'd sink it in the ground if you can, if you can't bring it into a frost free place, planted deeper than the present soil level, and then put a nice thick mulch over it when the leaves have gone.
If you have a cool unused room in the house let it gradually dry off and ignore it until early March, when you can spray it with tepid water, water it gently and gradually start it into growth. Don't cut back until you see new growth at the base, and then cut off all the old stems as they seem to grow more quickly from the base than from the old wood. You'll get much earlier flowers this way.

I agree with Badfish and Bamboo about the lack of pruning now and think Steragram's idea to sink the pot in the ground makes a lot of sense