If you have a large pot upend it over the rhubarb . Use a mulch around the root . It will be protected from frost. I always force rhubarb like this. You will have long tender stalks in a few weeks if the weather is mild or few months if it turns cold. Happy new year.

Remember though that if you do force it you should not really use it the following year to give it time to recover. So if you have enough it would be better to cover only some of it.
If the unprotected stalks do get frosted later the plant will recover later.

I always put something like an old dustbin or vegetable oil can (could be scrounged from fish and chip shops or cafes) with the top and bottom taken out over the top of the rhubarb. This doesn't exclude the light but creates long stems at the expense of the leaves. You can then mulch the emerging stems with straw or woody compost to insulate the plant from the frost and cold.