You can check “Elevation” as an additional output of the RD Terrain Correction. Then you have a product with both the S1 DEM and the the ArcticDEM used for ortho-correction.
You can then create a scatter plot of both products to see how well the rasters match for each elevation range. This maybe helps you to build a regression to compensate for a systematic offset.
Generally, you shouldn’t trust minimum/maximum values in the predicted elevations, because they are often the ones caused by unwrapping erros in areas of low coherence.