We also use the auto switch over capability. Used to leave the spare tank turned off at the valve, until I had to go out in 34 degree driving rain and open the valve one night at 4 am. Checking the tanks is now just a normal part of my daily / weekly normal routine. Never worry about running out because I know when a tank is empty, and I now get it refilled within a day or so.
Used four 30 lb tanks a month in Fort Davis, TX in Dec, never a problem, even with 3 nights down to 19 degrees and 28 nights below freezing.
Of course, it is easier for me to get in the habit of checking the propane usage because we are full-time. Some summer months we go 3 months on a single tank.