Prepare the ranch dressing: In a medium bowl, combine all ranch dressing ingredients. Mix until well combined. Add half & half if you prefer a thinner consistency. Cover and refrigerate for at least 1 hour, or up to 3 days. The flavors improve as they meld.
Marinate the chicken: Trim excess fat from chicken thighs. If any pieces are significantly thicker than others, butterfly them with a sharp knife for even cooking. In a bowl or zip-top bag, combine chicken thighs, seasoning, pickled jalapeno juice, and oil. Mix well to coat all pieces. Refrigerate for 2-4 hours.
Cook the bacon: Preheat your griddle to medium-low heat. Lay out bacon strips in a single layer and cook until crispy, allowing the fat to render. The bacon grease should flow downhill on your griddle, creating a cooking zone. Remove bacon and set aside, keeping the griddle at temperature.
Cook the chicken: Place marinated chicken thighs whole in the bacon grease zone on the griddle. Cook for 5-7 minutes per side, or until internal temperature reaches 165°F. Keep the chicken whole during cooking to develop a flavorful sear. Remove from griddle and let rest for 3-5 minutes.
Toast the hoagie rolls: Melt butter on the griddle. Split hoagie rolls and dip the cut sides in the melted butter. Sprinkle with garlic powder and seasoned salt. Toast cut-side down on the griddle until golden brown, about 2-3 minutes. Remove and set aside.
Assemble the sandwiches: Chop the rested chicken into bite-sized chunks. Lower the griddle temperature slightly by adding a small amount of water to cool it down. Place chopped chicken on the griddle in portions matching the width of your hoagie rolls. Top each portion with 2 slices of cheese. Add a splash of water near the chicken and cover briefly to help melt the cheese without overcooking the chicken.
Build the sandwiches: Layer 2-3 slices of bacon on the bottom of each toasted hoagie roll. Top with the cheesy chicken mixture. Drizzle generously with homemade ranch dressing. Add the top bun and serve immediately.