Whats the typical time on current orders?
It depends on the dealer and the trim. Generally 4-6 months. You can call around and find an unsold allocation - use forum spreadsheet to find desired trim at a dealer near you.
Here's what you can do. Go to your preferred dealer, ask how many orders for Tellurides do they currently have (A), ask how many on average they receive per month (B), then divide A by B and you'll have an estimated timeframe. Of course this can vary... but not a bad place to start.