How big is your garage?
These machines do like to be used - nastiest thing you can do to them is let them sit for months on end. That said, the Canons do run clean processes automaticaly.
I've run a couple of ipf - 8300 and 8400 under moderate volume, in a workspace that is typically under 40%RH. I have a small shelf of dead printheads (possibly the 8300 was a yellow citrus fruit in disguise, but that is what warranties are there for), but these are a quick swap out, plus a glug of ink.
The 8x00 is way more forgiving of low RH than (our still running) 9800. You do get clogged nozzles, but less so in my experience than on the Epsons. I believe that Utah is somewhat drier than London, but a relatively small room with several MacPros, multiple screens, and aircon can also make a pretty unforgiving environment!
At that price, if it were available leftpond, I'd buy two, and store one for the inks and spare heads