Distributed voltage control using centrally supervised reactive power setpoints is a means of operating distribution grids to the specific demands. However, this way highly depends on the structural integrity of the communication link. To maintain the optimized setpoints even when the link is broken, this paper proposes a Q(U)-fallback solution. The presented methodology aims at the necessary tuning of the reference voltage with explicit consideration of the steady state error inherent in the Q(U)-control. Furthermore, this approach is extended for a set of forecasts. In addition a stability assessment of the Q(U)-characteristic is included. Based on this, the performance is presented using simulations in a benchmark grid.