I believe Garrison was actually around at least 10 years. It was quite the rising star in Canadian start-up circles in the early 2000's or so. I think they got into debt and liquidity trouble trying to grow too fast.
Methinks the guitar making biz is a tough gig, especially if you go cutting edge. CA just bit the big one. Too bad as those were also pretty cool guitars. No telling what the future holds for Rainsong either.
The biggest problem with any humidity issue is not the the humidity level itself, but rather the swing in humidity levels as the seasons change. I live in the Northeast US. In the summer, you can see RH rise above 70%, so I run the A/C even if it's not all that hot. During the winter heating season, indoor RH will typically fall to the mid-teens if you don't humidify. It will fall to 8-10% if your abode is forced hot air. If you use a wood stove, it's probably more like 2 (the Sahara is moister than that). The humidity yo-yo will destroy anything from a custom guitar to a shipping pallet over time. Given enough time, it will even attack and destroy the neck and fretwork on a metal-body reso.
We've got baseboard hot water and still, in the winter, I have 1 or 2 clay canister humidifiers in every case (including my metal reso's and woodwinds) and I run humidifiers as needed throughout the house, including the basement.
If you value your instruments . . . . As I said, it cost me 2 Martins to learn this the hard way.
The Garrison bracing system is more sensitive to humidity flux than an all wood brace (even the AG series has a composite top brace), but, if you monitor and manage, there shouldn't be any problems. As I mentioned previously, I've my G4-12 is 5 years now and my G20 is 8.