A two-terminal multi-state network (TMSN) is a network (system) with multi-state subsystems (arcs and nodes) and two terminals (source and sink nodes). In a TMSN, system reliability is a widely applied performance indicator of demand satisfaction. To assess system reliability, previous studies relied on knowing the upper bounds (d-MCs) or lower bounds (d-MPs) for specified demand d and a given capacity probability distribution. Accordingly, a novel minimal cut (MC)-based simulation approach is proposed, which does not rely on knowing the d-MCs and capacity probability distribution. An algorithm based on Monte Carlo simulation with demand confirmation via MCs is developed to estimate system reliability. In addition, an extension with a time attribute is examined to investigate the reliability degradation with time. Additional case studies, including a real-life instance of the Taiwan Academic Network, are analyzed to validate the scalability and applicability of the proposed approaches.