Automobile GPS Features

This afternoon, while I was at work, I received a text from my wife that we were going to meet family at a restaurant after work. That would mean that I would go right from work, to my car parked in a parking ramp, and head right to the restaurant.

I still have an old Garmin Nuvi 360, but it does have current CN maps on it. Now I know that when I am parked for a while the Nuvi takes some time to acquire signals from the satellites. It takes several minutes after I am out of the parking ramp to acquire signal. I was anticipating that, so I ended up using Google Maps on my phone. Anyway, I was wondering if there would be a to configure a Garmin Nuvi so that it would acquire satellite signals every few hours and then go back to a dormant mode. Obviously, one of the big concerns is power consumption. Do GPS devices take a lot of current just to acquire the initial fix? Also, my Nuvi has a pretty fast "warm start" and not such a fast "cold start". Does anybody know how long it takes for the Nuvi to go from "warm start" to "cold start"? I know if I sit for 8 hours, it is a "cold start". I think if the car sits a mere hour it might still be a "warm start". So, I guess some time between 1 and 8 hours it goes cold.

Also, one of the features I really liked about a newer GPS that I tried recently was something I will call "auto complete". I am not sure what Garmin calls it, but basically as I am entering the name of a POI, say I am looking for coffee, as I am tapping in "S-T-A-R" it will offer Starbucks as a choice very quickly. Is that as a result of a faster processor in the something like a Garmin Nuvi 3597 or is it something else like software?