There are several semi-empirical models available in literature that correlate the intrinsic hardness of cemented carbides' constitutive phases and certain microstructural parameters, such as mean WC grain size and Co volume fraction, with the hardness of the cemented carbide. Nonetheless, such empirical relations fall short on predicting the behavior of materials other than WC-Co which they were fitted to, limiting their applicability on materials with diverse particle size distributions, alternative binder systems or with additional carbides (γ-carbides). Additionally, current models are limited to the prediction of room temperature hardness. Framed in an Integrated Computational Materials Engineering (ICME) approach, this work proposes several models to be integrated into an already validated semi-empirical approach to describe the hardness of cemented carbides as a function of temperature. First, new microstructural descriptors on the particle and binder size distributions are proposed to enable a better understanding of the influence of polydispersity and of the addition of γ-carbides on the hard-to-soft phase reinforcement. Second, a validated Peierls-Nabarro-based model is used to describe the intrinsic softening of the hard phases with temperature. And finally, the importance of the microstructural changes happening under stress at high temperatures is highlighted and its effect on hot hardness is introduced into the model. These upgrades increase the theoretical and physical base of the modeling tool providing a physical meaning to all the modeling parameters, lowering the need for numerical fitting, making the model more generic and bringing additional information into the micromechanics involved in the softening of cemented carbides.