What could designing for carbon reduction of heating and cooling in commercial settings look like in the near future? How can we challenge dominant mindsets and paradigms of efficiency and behaviour change? How can we help build worlds through our practice that can become future realities? This paper introduces the fictional consultancy ANCSTRL.LAB to explore opportunities for making space in research projects that can encourage more systems-oriented interventions. We present a design fiction that asks `what if energy management and reduction practice embraced systems thinking?'. Our design fiction explores how future energy consultancies could utilise systems thinking, and (more than) human centred design to re-imagine energy management practice and change systems in ways that are currently unfathomable. We finish by discussing how LIMITS research can utilise design fiction and speculative praxis to help build new material realities where more holistic perspectives, the leveraging of systems change, and the imagining of post-neoliberal futures is the norm.