The way out of the trap is not so simple, but I recommend getting a cabinet that can do what you want without the help of the 210's in the combo. It might not be perfect with the c210, but would give you more volume when you need it.
Then, down the road, perhaps get a light power amp (my Crest proLITE 3.0 non-dsp is 11 lbs), and rack it with a preamp in a 3U rack bag. That is likely to weigh ~24 lbs or less. You then have a great head, a great cab, and a combo you can use at rehearsals.
For extended range instruments, it seems to me a full range system would be preferable. Have you investigated some of the current cabs that are more like the PA cabs you have, but are more portable?
In the case of my cabinets which are a fEARful full range cabinets, some have one 12, some two 12s, some one 15, and at times I use two 15s. They all sound exactly the same, because they are designed to sound that way.
I am considering building a Bill Fitzmaurice Omni Full Range. I currently use full range PA speakers, but BFMs 3 way Omni's have a wider frequency response and a very attractive flat curve. Arguments in my mind against it are time and unforeseen costs, although I could build and use that cab with the combo or my rack setup, which is already similar to the rack setup you suggested (just heavier).
It sounds like your current/previous "main rig" is kind of thrown together anyway. You might think about coming up with a holistic plan for starting from scratch and selling off everything.
I guess you use rental practice space by the hour (rather than a spot where your gear stays set up all the time)? Some of the old school stuff is super cool albeit heavy, but it doesn't really sound like you have the best of that stuff anyway. Think to yourself what you really love about that setup, other than that you already have it? And think about what you are looking for tonally and functionally.
Presumably with a light rig for practice, your main heavy rig would just come out for gigs? And maybe not even then? But what if you had something that was portable and capable of holding down a gig?
I would reassess what you really want, and do whatever you need to to get there, even if it means selling everything and starting fresh but getting exactly what you need (or as close as possible in your budget). It doesn't sound like your current set of gear is really maximized for any particular thing.
And you're talking about hauling around a carvin power amp and yamaha PA speakers, including a 70+ pound rack. Not trying to "rig shame" you, I'm sure what you have is fine and you probably bought it for a reason, but in today's technological and economic climate, even on a shoe string budget I think you could do better.
I may sell off current components as I figure out what gets me the most milage. I did throw something together based on what was available and affordable on short notice. It's true that better gear comes around at my college student budget with generous application of patience, but I was asked to start playing with about 2 weeks notice, so I took what I could get. In my defense, It sounds really good for a piecemeal rig.
We get a 2 hour block for use of one of the multi-purpose rooms at school. I can't leave my gear there, so I'm setting up and tearing down just for practice.
SWR's tone compliments my playing style. Other amps do too, but I'm less familiar with dialing them in. While I would have preferred a Redhead/Super Redhead, all the ones in my budget came with shipping charges that killed the deal. The WM combo was close enough to pick up in person, and it actually sounded great! I wasn't expecting it to because it was the budget line, but I set the knobs how I used to, started playing, made some minor adjustments, and had a mix-cutting groove tone in no time.
Ideally, I plan on practicing with the combo and only gigging with my rack rig, but an extension cabinet opens more power and driver surface area, which leads me to believe that I could gig with it by adding a used or DIY cab. This time I can bargain hunt and play the waiting game as I have a very capable rig in the meantime.
I'm not ashamed of my heavy rig. It works well and has an absurd amount of power. It will probably replace the bands PA if I can find the right cab for the combo. As cool as the new stuff is, I need to try before I buy and the music stores in my area have bass sections that seem more of an afterthought (i.e. none of the stuff that gets great reviews and recommendations on here). I can choose current production run Fender, Ampeg, TC, Hartke, or Markbass. None of those (at least that the stores stock) can get as loud as I play (with my amp master between 2-3) without distorting in a bad way, which leaves a bad taste in my mouth on class D. I'm sure Mesa, Genz Benz, Quilter, and others are probably much better, they just aren't available where I live.
