Thanks for prompting me to think this through. This is how I see it now.
There is no existing mechanism or process by which the community can reach a proper democratic/decentralized decision, nor any prospect of such in the near future.
I was co-founder of the wiki (with @CosmosX who is no longer active), I’m the registered owner of the domain, and I paid for the first two years of hosting, to 5 March 2020 (of which the first year costs were recouped from donations and the second year costs are still outstanding).
Therefore I see it as my responsibility to care for the wiki until such time as the community can make proper decisions.
In the meantime, I will retain ownership of the domain and Bureaucrat status on the wiki.
As per my retirement announcement I will no longer feel duty-bound to make regular contributions and will hand over the Twitter account to a suitable person, who will be expected to regularly promote the wiki. I will provide any reasonable assistance that contributors might require on a best efforts basis. And having received a number of offers of free hosting, I intend to choose one and complete the migration process before the end of the current period ie 5 March 2020 at latest, but probably much sooner.
I believe that covers all the main issues, but of course everyone is free to comment. 