This recipe works with either domestic or wild turkey. I've found that of all the animals with a wild and domestic equivalent, turkey is the closest in flavor. A good heritage breed turkey is very similar to a wild one. But even a butterball would work well here. They key is low and slow. This is barbecue, not grilling. Set your grill up where the fire is on one side of the grill, and the turkey thighs are on the other. Cook the turkey, flipping and painting with the BBQ sauce, every 15 to 30 minutes until the meat wants to fall off the bone. This should take between 2 to 4 hours, depending on how old your bird was; and old tom could take 4 hours.
Get your grill ready as described above. Coat the turkey thighs in the vegetable oil and salt well. Lay them skin side down on the cooler side of of the grill. Cover and cook until the meat is just starting to fall off the bone, flipping every 30 minutes or so to paint with the maple-bourbon BBQ sauce. Let the turkey cook without sauce while you make it.
Once the turkey is on the grill, make the sauce by sauteing the grated onion in the butter for a few minutes. You don't want the onion to brown, but you do want it to cook enough to lose that raw onion smell and flavor. This should take 5 minutes or so on medium heat.
Add the remaining ingredients and mix well. Boil this down by 1/3. Adjust for heat and salt. If you want, puree the sauce in the blender. I prefer to puree my sauce because it will be thicker that way. Return it to the stove top over very low heat. Stir from time to time.
When the turkey is done, shift it to the ho side of the grill, skin side down, for a few minutes to caramelize the sauce. Paint with a little more BBQ sauce right when you serve.
Notes
Serve with a veg and starch. Since it's spring I chose mashed potatoes and grilled asparagus. Oh, and beer is my choice here, not wine.