Someone at my school suggested setting up a virtual reality lab with adequate computers. I pointed out that that defeats the whole purpose of using virtual reality at all --- having students sit side by side and going inworld
A lab won't work for the snow day, but for education generally, I could think of several methods that should work in the lab, and I probably could find some evidence to that effect. In addition, before trying off site use, I would suggest an initial on site introductory session in a lab with suitable computers would be highly desirable, if that were possible. For a snow day, there are 2d teaching and conferencing systems of course.
a gaming rig capable of running any OpenSim viewer
Just to clarify, you don't really need an actual gaming rig. True, many desktop and laptop computers can't handle a standard viewer, or they need horribly low res graphic settings. However I have been able to run OpenSim on computers which would now be 6 years old and had very poor 3D performance. My usual "mobile" (sort of) OpenSim device is an old laptop, again about 6 years old. However it does have an Nvidia chipset. That's why I bought it. So whilst many computers will be difficult, It doesn't actually take a gaming computer, or anything near what a gamer would expect. It does need a person to be thinking "3D graphics" when they decide what to buy, and hardly anyone does.
Having said all that, distance learning, tutorials and meetings were partly what hooked me in to VW, and this general problem of not knowing whether a home PC will be suitable is a killer. I even established that the firewall was not a problem for our users. If the server was on our intranet, anyone with an account could VPN in securely. But the computers aren't built for this. There's no demand. And as long people can't run the viewers, there won't be.
A few days ago I tried some viewers on a several years old office PC I have, which ought to be fine, but barely can load a viewer. I'm sure I've seen SL running on an early model netbook, so I have a small personal challenge now to see of I can get that PC sorted out.