Splitting it should lower your cook time some. If you plan on 1.5 hrs rest, pulling it at about 5:30, I would still say start it around 6am. Monitor your temps closely, especially when you hit the stall. If your stall lasts too long and starts to make you nervous, there's nothing wrong with the good ol' Texas crutch! Also, what's your rest method? I find that if I reach my temp much earlier than I plan to, I can rest for as long as I need by wrapping in foil, then a layer or two of towels, and into a dry cooler. This has held within 10° of my temp for up to 3 hours for me before.
Hope it works out for ya!