Cool - then I still beat feet to get outside. Knowing where the static shock came from ("the clump of bushes" if nothing more). AoE spell on the bushes just before I go through the barrier, to discourage pursuit. Of course I zigzag as soon as I am outside.
Good luck trying to chase me and stay hidden - Hiding takes an action, and yours is busy casting that long spell - at the same time. In fact, good luck carrying the material components (yes, plural) for Private Sanctum and having a hand free to handle any other spell's material components at the same time.
10 min = 100 rounds. Got a 100 SP stash as a Sorcerer8? Do explain how. You cannot rest while you are out ambushing people. If you run out of SPs part-way through, what do you stop doing so you can break down more spell slots?