Put the water and sugar in the crock pot and turn on high. Stir to dissolve the sugar. Juice 4 of the clementines and add to the pot.
Add the rest of the ingredients and heat until the wine just gets to a simmer. Then turn the dial to the 'keep warm' setting and let it sit for about 30 minutes before serving.
You can strain the wine before serving, or not.
For the Holiday version, the process is the same, omit the clementines and use cranberries and rosemary.
Video
Notes
You can double the recipe, but the actual whole spices don't have to be doubled.
You can make the mulled wine a day ahead and refrigerate. Then strain and rewarm in the slow cooker. You can add a few fresh orange slices.