A tenderloin only takes about 30 minutes to cook. Either on the grill and keep rotating or on a grill pan and finish in the oven. The rice can be cooked when needed or even the day before. No crockpot needed!
Aside from all of that you say you don't want to leave your oven on all day - - - - your oven is not needed. And aside from ALL of that
the meal you have in mind won't take that long, which IS a wonderful thing!