Before you do any repitching, you must get the temp up first. Otherwise the new yeast will just settle out with temperature shock too. That strain is a high flocculator, so if the temp is to low it certainly drops out early. Get the temp up to 72F and try the following ideas.
Then I'd rouse the yeast you have a bit and see if it will come revive and be active. You can pick up the fermentor and gently swirl it until the you get enough liquid movement to get the cake moving, but that can be very tough. A better option is to go in with a sanitized racking cane and gently agitate the cake a bit to break it up. The best option would be to attach a CO2 source to your racking cane and use some CO2 flow to bubble the cake up.
Keep in mind that bubbles in the airlock after rouse an the temperature increase won't indicate activity. It will just be residual dissolved CO2 coming out of solution. You'll have to monitor the gravity.
If you didn't aerate the wort well, or pitch yeast from a LARGE and very active starter there is no way you could expect that yeast to finish a 1092 wort. So you will really need to pitch more yeast.
I'd suggest getting another good starter going of the same yeast actually. The Ardennes strain is a good fermentor. Get that temp up and pitch another good starter of the same yeast. You can try an neutral ale yeast, but the Ardennes is better suited to this high gravity wort than a US05 or WLP001 or WY1056.
Another option would be to pitch two rehydrated packets of dried yeast if that's easier for you. But you should be able to rescue this beer with more of the same yeast.