Leave preamp on all day, off at night

I would really like to preserve the life of the ref3, and not waste it on background music and TV etc.

My suggestion is use the quad 99 with another power amp or use a AVR/integrated amp, connect to a speaker switcher like the Niles SPK-1.
For background music and TV, you can turn off both ARC ref3 and gs450.
For critical listening, turn on the ARCs, the ref3 12v trigger will switchthe speakers from quad 99 system or AVR/integrated amp to gs450.
One thing to bear in mind, you need to get an amp or AVR has enough power to feed your speakers.

Are the tubes powered when ARC is used in bypass mode?

Ideally you would have a dedicated room with your good gear for critical listening, and another system in the living room for your wife and kids to listen to background noise.

Option B would be as others have said. Add another system in the living room for background listening. 

 Save your good system by leaving it off and untouched except for your critical listening sessions.

Hi devesh.  An audio tech told me not to power off my LS26 for a short period, it is better to let it ON.  What shortens the life of Tubes is mostly the on and off ; Cool and warm.  Usually I made ~7000 hours with my 6H30.  It plays ~ 8hours a day

The question of whether to leave preamp on/off reminds me of a question years ago about whether you should turn off your home computer or just leave it on all of the time.  I think it depends.

I will say this with respect to computers having worked in IT for 25+ years.  Computers: Application, Web and Database Servers or any hardware that constitutes a network run 24/7.  They may occasionally get rebooted but otherwise, they're always on.

Computers in an office area sometimes get powered down, sometimes they don't.  The problem with those that get powered down is that they don't receive updates or security patches until they're booted up again.

As far as audio gear (tube gear in particular), I have mixed feelings.

Having said that, I own an Audio Note OTO SE Phone Integrated.  I will sometimes allow it to be powered up for 2-3 days at a time.  I think the longest time was for a 7 day period when it was initially burning-in.

My Nottingham Interspace Jr. TT on the other hand has no on/off switch.

Peter Qvortrup was once asked (and most likely has been asked several times), why does he put the power switch on the back of Audio Note components.

Peter's answer:  So people won't turn them off.