Well Otawan:Isn't it strange that I have to answer yes and no.
Here is Why:
For you in Otawa Canada,if it dies to ground ,the fruits will ripe in October,when to cold and so fruits are not full Flavor,so for you No.
For Dennis,in much warmer climate,but with cold winter sometimes,if killed,the tree grows back and get ripe in September ,and the days are hot,so it still makes better fruits than the year before because the plant has stronger roots!.
So for Dennis the result is yes,his tree improves year after year even if it starts from soil level again.
So I would say you take care of your plant not to die to soil level,just peg the branches down and cover them with about 6 inches of soil,and you will be ok.
People Back in Transilvanya cover the whole Vineyard,hundreds of vine every year with soil,and have some of the best wine in the Estern Europe,champaine and spumante too.
Think about covering 600 grape vines manually with the How,and then uncover them in the Spring,every year.
Planting tree in a warm zone,like yours?
Best in Spring,after danger of frost in your area,let say,1st of April,or earlier.
You can also plant immediatelly after the first light frost,when leaves are fallen out,at least 3/4.of them on ground.
Your tree will survive both way but Spring is sure shot .
Do not take more tree out of pot than you can plant in 1 hour.
Dig holes first. Pour one bucket water in every hole before planting.