Plasmonic nanostructures have demonstrated significant potential for engineering the intensity and polarization state of light with further opportunities to actively manipulate them by external stimulation using nonlinear effects. Plasmonic metamaterials composed of arrays of vertically oriented metallic nanorods have shown a dynamically tunable optical response based on the change of the electron temperature. The modulation of the optical properties is particularly pronounced in the epsilon-near-zero regime and can be further enhanced by nonlocal effects. Here, we experimentally study the optical properties of gold nanorod metamaterials with a strong nonlocal response under optically-induced heating, exploiting temperature dependence of the metal permittivity. Recovering the Stokes parameters of light transmitted through the metamaterial, we demonstrate the change in the polarization of the transmitted light by more than 20% for temperature changes under hundred degrees. Combined with a numerical analysis, this shows the possibility of controlling transmission and polarization state of light by using metamaterial-assisted thermal modulation.