Any issues with upgrading a phone after you pair a watch to it? I have both an 8 plus (from cell carrier) and an LTE watch (from Apple) arriving tomorrow. Basically wondering if I need to play it safe and upgrading my phone to the 8 plus first, then pair the watch with the new phone. Or if the watch arrives first if it is ok to pair it to my existing iphone and then some ours later re-pair it to the new phone? I know, such impatience.