In loudspeaker-based sound field reproduction, the perceived sound quality deteriorates significantly when listeners move outside of the sweet spot. Although a substantial increase in the number of loudspeakers enables rendering methods that can mitigate this issue, such a solution is not feasible for most real-life applications. This study aims to extend the listening area by finding a panning strategy that optimises an objective function reflecting the localisation and localisation uncertainty over a listening area. To that end we first introduce a psychoacoustic localisation model that outperforms existing models in the context of multichannel loudspeaker setups. Leveraging this model and an existing model of localisation uncertainty, we optimise inter-channel time and level differences for a stereophonic system. The outcome is a new panning approach that depends on the listening area and the most suitable trade-off between localisation and localisation uncertainty.