Cook bacon until crispy. Set aside. See notes for bacon cooking tips.
Bring a large pot of water to boil, make sure there is enough room for your peeled cubed potatoes. Boil potatoes about 20-25 minutes, until a piece is fork tender when pierced. Drain water from potatoes.
Next, Add all the dressing ingredients in a bowl; apple cider vinegar, lemon juice, Dijon mustard, sea salt, pepper, olive oil, blue cheese salad dressing, and sour cream, whisking after adding each one.
In the large bowl, re-whisk the dressing and in the bottom of the large bowl, then place the drained potatoes into the bowl.
Stir to combine. Next add crispy bacon pieces, crumbled blue cheese, chopped parsley, sliced green onions, chopped celery, and thyme leaves.
The warm potatoes will help melt the blue cheese and absorb the dressing. Toss well and store in a sealed container in fridge, gets even better by the next day so it's perfect to make ahead.