Looking for a tube preamp with remote control.

Your Cambridge streamer appears to offer volume control like the BluOS product I use.  Just set the volume control on your preamp to to the maximum volume you are likely to listen to with the volume on the streamer at maximum.  After establishing that value, use the streamer volume app to attenuate the volume to your preferred level.

Buy a used ET 6 SE , sell yours and your bottom line should be around $3k when done 

I had great results with Odyssey Audio’s Candela. High value for the money and Klaus’ service is excellent.

Perhaps checkout the Quicksilver Remote linestage. I've heard the non-remote linestage and thought it was excellent. I'd like to add one to my arsenal at some point. 

Take a look at Schiit Audio, they make a tube buffered unit with  remote volume and switchable inputs.   Put it in the tape monitor space on the CJ.  More importantly, you still use your CJ as the main preamp.