If you do not see live buds on May 1,on upper branches,then that wood is dead .
However the plant is ,in most cases alive and will grow new limbs later in May and June.
Some early leafing cultivars got live growing buds here,now, ,on in ground plants:
Adriatic JH,Negretta,O"Rourke Celeste,Vasilika Sika,Malta Black
As For Kadota,in NJ,my opinion is,it is a poor choice for.
The fruits ,will not ripe properly due to lack of sufficient heat units during Summer.
Try growing it in a pot and use the sunniest location in your garden,to get positive results.