The cold tolerance, phenology, yield, and fruit maturity of alternative red- and white-skinned wine grape cultivars (Vitis vinifera) of European origin were compared with those of ‘Merlot’ and ‘Cabernet Sauvignon’ over two growing seasons in southwestern Idaho. Variability among alternative cultivars was detected for cold hardiness, onset of phenological events, yield, and fruit composition. The red-skinned cultivars Montepulciano and Tinto Cão were the least cold hardy of the alternative cultivars. The red-skinned cultivars Aleatico, Aglianico, and Graciano had similar yield but matured later than the leading cultivars Merlot and Cabernet Sauvignon and were among the more cold-sensitive alternative cultivars. ‘Grüner Veltliner’, ‘Sauvignon Gris’, and ‘Trousseau’ cold acclimated early, had high midwinter bud cold hardiness, and had similar or higher yield and fruit maturity as the leading cultivars. The white-skinned cultivars Verdelho, Fernão Pires, Sauvignon Blanc Musqué, and Sauvignon Gris had similar or less vine injury, similar or earlier phenology, and similar yield and fruit maturity as the leading cultivars. The large berry size of the red-skinned cultivars Trousseau and Touriga Brasiliera warrants evaluation for wine quality. The cultivar variability identified in this study for cold hardiness, phenology, cluster architecture, and yield provides a useful guide for cultivar site selection.