I anticipate being in a similar place at some unpredictable time in the future. I have a 2013 vintage 3880 which seems to chug along beautifully. I do not want to say anything that would anger it or upset it because I genuinely love it, but nothing lasts forever.
I have already spent way too much time speculating about what I would do should my beloved 3880 pass on. I think my first choice would be a P5000, built like a tank, sufficiently large cartridges that the cost of ink switching becomes insignificant, vacuum paper holding. Great, but try to find one. If they're out there, I've not been able to locate one. Were I able to, I might just buy one as insurance.
The 24" printers are an entirely different world, size is not an issue for me but their costs and potential maintenance should one break are daunting. I've flirted with the idea of a 24" printer but keep retreating. I use Quadtone RIP for my monochrome images and it does not fully work on the P900 or presumably the 24" P7570 as well.
The P900 makes lovely color images; I've seen some but I don't want to give up the Quadtone RIP. It also has tiny cartridges and their accompanying high ink costs as nicely documented by tastar.
I don't know whether my thoughts are helpful to the OP or not but thought I'd share since we're all one step away from him or her.
Eric