Constantlaughs
Go for it man....nothing to lose.
I am in a worse zone than you, 4B, and I am going to set out a few more clones.
Some of the Amstel x Mitey Mite i put out at first of June is flowering already...(only 12 to 18 inches tall)...oh well.
I plan on putting another 10 out as they will get at least 4 to 5 weeks more of Veg...and shhould do fine. If you can find yourself some clones that are already 3 or 4 weeks old you will be good to go.
As illegal said you will get less yield....but I have had late starts before with some strains and still got a decent harvest.
Get a good spot, use decent soil mix such as FF, dig nice wide and deep holes,do a little LST and you will not regret it.
I like to think a positive attitude gets you half way there
The experience will also help for future grows when you can start on time
Let us know how you make out.