I think the simplest solution for this problem is to give super active package creators/maintainers free hosting.
A simple “apply to be a community partner” form on galaxy’s site… if you’re good, then you can get a partner account… hopefully they’ll keep the bar relatively low… like somebody who maintains (or plans to maintain) 3+ solid packages (or whatever the threshold may be)
This should be simple enough to implement for MDG and let’s the great package community get what they need.
I didn’t realize how much I use the demo sites until recently… so it’d be a shame if they disappeared.