I've just noticed that the AUK web calendar now offers an .xls or .csv download (maybe it has done for ages).
I downloaded the file, re-arranged and formatted it according to the instructions here:
https://n8henrie.com/2013/05/spreadsheet-to-calendar/#Formatting, imported it to Google Cal and now it's available as an .ics file, here:
https://calendar.google.com/calendar/ical/knpb53dru2glvif2b08q0gsqeo%40group.calendar.google.com/public/basic.icsor simply as a public google calendar, here:
https://calendar.google.com/calendar/embed?src=knpb53dru2glvif2b08q0gsqeo%40group.calendar.google.com&ctz=Europe%2FLondon , which you can add to your google cal account.
It won't update any event details if they are changed on the AUK site from now on. This would need to be done manually (& I'm open to amendment requests).
And I make no guarantee of the accuracy of the event details. For example, for Arrow events, where there is no set start time, I have had to put in a start time just to make it work. Each event on this calendar should have a valid hyperlink to the AUK event page within its details, so you can easily click through to check that all is as you expect.
AUK's online calendar works pretty well and is very smooth nowadays, and of course you can very usefully filter your search... but sometimes you just want to be able to see the rides via your phone app easily too.
Ideally I would make different google cals for the different regions, or for different ride lengths (eg one cal for 200s and shorter, another for anything longer than a 200). But for now it's just all in one big thing (286 events).