This particular variety isn't frost hardy, so needs to be brought inside or grown in a conservatory for winter. The fact it has green leaves still at the top would indicate its alive - although pruning isn't necessary for these, I'd be inclined to cut it down in hopes of generating new growth, but I'd wait till mid to late March to do that, unless the weather carries on being mild. Feed with a general purpose fertiliser after cutting down.

Thank you. I'll try that.