Fry bacon until crispy. Drain on paper towels, then chop into tiny pieces; set aside.
Coarsely grate potatoes, apples, and onion; drain well (you can do this by putting the mixture in cheesecloth or a clean hand towels and ringing it dry). Once dry add mixture to a large mixing bowl; add all of the remaining ingredients (including the bacon) and mix together until well combined.
Cover and place mixture in the refrigerator to rest for 1 hour.
When ready to fry:
Pour oil into a frying pan over medium-high heat. Once the oil is sizzling, drop large spoonfuls of the mixture into the pan and fry until golden brown on both sides and cooked in the middle, about 2-3 minutes on each side. Repeat until all fritters have been fried.
Drain fritters well on paper towels. Top with aioli and fried sage. Serve at once.
For the aioli:
Whisk sour cream and yogurt with garlic, lime juice, and chipotle hot sauce to taste. Season with salt and pepper; chill until ready to serve.
For the fried sage:
Heat the oil in a small saucepan over medium-high heat.
When the oil is sizzling hot, add the sage leaves. Fry for about 15 seconds, turning once with a slotted spoon or tongs (don't let the leaves brown).
Transfer the leaves onto a paper towel-lined plate. The leaves will become crisp as they cool. Sprinkle lightly with salt.