Let's be honest, there's no way a deal would happen in 2 years. It was always going to end in some transitional agreement or some terrible reverting to WTO rules (and I seem to remember the EU previously favoured a transitional agreement). Cutting the negotiating time down may actually increase the chance of ending up with a transitional agreement given there'll be even less negotiating time.
Let's be honest, there's no way a deal would happen in 2 years. It was always going to end in some transitional agreement or some terrible reverting to WTO rules (and I seem to remember the EU previously favoured a transitional agreement). Cutting the negotiating time down may actually increase the chance of ending up with a transitional agreement given there'll be even less negotiating time.