1 gas price?

I was wondering about setting my gas price to 1 I am new to etherium and I wish to move some etherium I have mined to another wallet but gas price is a big deal since I mined like 20$ and I dont want to pay a bunch of money. I have no problem with waiting 40 minutes for a transaction this calculator says that i will have to wait 47 minutes so whats the drawback? https://ethgasstation.info/calculatorTxV.php if 1 gas price doesnt work whats the lowest that will?