Purely hypothetical as SONAR/CW software would probably run for 10+ years even if they stopped development today.
 
None the less, what DAW would be your goto assuming you had to drop SONAR/CW?
 
Please note: if you are not a SONAR/CW user your response is moot because for you SOANR does not work.
 
I'll start: Most likely Studio One Pro, but a slight possibility for Reaper as the cost is lower. Disclaimer I have up to date licenses for both products.
 
BTW I use Mixbus as mixing environment not as a DAW and so I would continue to do so. And that is why it is not in consideration for me.
 
<edit> BTW, since this is a POLL just pretend that you all get Best Answer because for you it actually is the Best Answer.

Hard to say since I haven't used another DAW since Cubase 3. Maybe Studio One if it's similar to Sonar.

I have current versions of SONAR Plat, SO3P and Reaper.  I've taken the time to get to know all of them, though not to the level I've used SONAR.  If SONAR quit working, I would go to Reaper without hesitation.  SO3 was easier for me to get started with, but once you get down with Reaper it the most powerful and flexible by far ...
 
... for ME.  YMMV

I'd probably give MOTU Digital Performer a shot.
It's what my mixer/co-producer uses, and seems to have similar workflows to how I use Sonar.
I haven't worked with anyone that uses PT, Cubase, or anything else in years, so i have no clue how those DAWs are working.

Most likely, I'd go with Studio One since I've had their Artist? version for years now. Installed and briefly used it about 5-7 years ago but IIRC, it was fairly easy to navigate. I'd be very disappointed if Sonar didn't work though....  

We're Bach.

Reaper

I wonder where it was Haydn...oh don't start that again...

I'm gonna answer this as if SONAR all of a sudden completely stopped working for me through some zombie ice magic anywhere at all. Like I could never ever use any current/previous/future version forever.
 
I'd use Reaper because I already use it quite a bit now as it is for stuff SONAR doesn't seem to like doing.
 
If I had money I'd consider Cubase and MAYBE check out the S1 and/or Bitwig demos.
 
If I had a LOT of money... I'd go back to Nuendo.

I'd give up music