Silent Mode Override during Do Not Disturb

I always have my iphone in silent mode (ringer switch off). I don't want to have to remember to turn it or DND on / off every time I am in a meeting. I have vibration on so if I do get a call, I can "feel" it. I use DND at night so that my phone doesn't light up when messages / notifications come in. I have it programmed to start DND at 11pm and end at 7am. I have DND set so my Favorites bypass DND. The problem is that since I have the phone in silent mode, if I do get an emergency call from someone on my favorites between 11pm and 7am, the phone will only vibrate (since the ringer is off). I tried using the emergency bypass setting under the ringtone option in the Contacts app, but this will bypass the silent mode all the time. Other than remembering to turn my ringer ON at night and OFF again in the am, is there a way to have calls bypass silent mode only during certain times?