Earlier quoted context omitted.
400K would go -fast- if they stuck to a traditional colo setup. Donations like this are rare and it may be all they get for a decade. Personally I would feel better about round robin across multiple maintainer-home-hosted machines.
I, personally, have a cabinet in a colo. With $400k, I can host it at that datacentre with the income from risk-free return never exercising the capital with 10 GigE, 3 kW of power. If I can do it, they can do it. Modern computers are super efficient. A 9755 has 128 cores and you can get it for cheap. If you've been doing this for a while you'd have gotten the RAM for cheap too. If I, a normie, can have terabytes of…
In any event if I was the volunteer sysadmin that had to babysit the box, I would rather have it at my home with business fiber where I am on premises most of the time because getting in and out of a colo is always a whole thing if their security is worth a damn.
Even given a frugal and accessible setup like that I can imagine 400k lasting 5 years tops especially if paying for the volunteers business fiber and much more especially given I expect some of it is to provide a sustainable compensation to key team members as well. Every cent will count.