Cold hardy? I'm guessing not so much for zone 5 based upon its description (but it is late harvest which often means late bud):
'Gratitude' has an exceptional crisp texture with seedless, green (white) berries. Berry weight averages 3.5 g and clusters can weigh up to 500 g. Harvest of 'Gratitude' is usually late August in central Arkansas with moderate yields. Skin is very thin and in most years no seed traces were found. Soluble solids content averages 19%, and flavor is neutral, similar to most Vitis vinifera table grapes. Fruit cracking was not observed, an exceptional characteristic for a crisp, thin-skinned variety grown in an area with rainfall near maturity and harvest. Clusters are usually very tight. Productivity is moderate. Negative characteristics for 'Gratitude' include occasional winter injury to vines and tight cluster fill.