Electric vertical take-off and landing (eVTOL) aircraft are expected to play an important role in future urban transportation systems. However, large-scale and standardized eVTOL operations are fundamentally constrained by limited onboard battery capacity and stringent temperature limits of batteries and electric motors, which are closely related to electric propulsion and thermal management configurations. To address thermal limitations, extensive research efforts have focused on thermal management systems (TMS) to regulate component temperatures within allowable limits. Nevertheless, the mission-level implications of thermal management have not yet been sufficiently clarified. Even when component temperatures are properly managed, the operation of TMS introduces additional power consumption that may indirectly constrain mission feasibility. This study presents a mission-level electro–thermal simulation framework to assess eVTOL mission feasibility under simultaneous energy and thermal constraints. Mission feasibility is evaluated based on the simultaneous satisfaction of prescribed energy reserve requirements and component temperature limits. Parametric analyses across ambient temperature and mission distance are conducted to identify feasibility envelopes that define admissible operational and configuration-dependent design regions. The results show that thermal constraints, through increased TMS power consumption, could become the dominant factor limiting mission feasibility even when temperature limits are satisfied. These feasibility envelopes provide practical design and operational insights for configuration selection under different mission and environmental conditions. The proposed framework provides a basis for eVTOL configuration analysis, mission design, and optimization-oriented studies under realistic operating conditions.