Start by prepping the guacamole. Pre-heat a lightly oiled grill or grill pan over medium-high heat. Place the ear of corn directly on the hot grill. Cook for 8-10 minutes, rotating the corn every 2-3 minutes, until the kernels deepen in color and are lightly charred in spots. Remove from the grill and let cool slightly. When cool enough to handle, use a sharp knife to slice the corn kernels from the cob. Briefly set aside.
Slice the avocados in half lengthwise, remove the pit, and scoop the flesh into a medium mixing bowl. Add the lime juice, chili powder, a good pinch of salt, and a few cranks of black pepper. Using a fork, mash the avocado until relatively smooth. (A few small lumps are fine.) Fold the corn, cheese, red onion, and cilantro into the guacamole. Taste and season with extra salt and pepper if needed. Press plastic wrap onto the surface of the guacamole (to keep it from browning) while you grill the hot dogs.
Score the hot dogs on the bias with the tip of a sharp knife. (This is optional, but I like to do it to help the dogs get extra crispy and absorb more smoky flavor.) Place on a lightly oiled grill or grill pan over medium-high heat and cook, rotating the dogs every few minutes or so, until they’re well browned all over. (This should take about 6-8 minutes.)
Assembly time! Spread the inside of each hot dog bun with a generous amount of guacamole. Nestle the hot dogs in the prepared buns and top with lettuce, tomato and hot sauce (if using). Garnish with a little extra cheese if you’re feeling particularly festive. Serve immediately.