That is the new book by Danny Dorling and Annika Koljonen, and I opened randomly to a page and saw a chart for Total Fertility Rate in Finland, 1900-2018. The numbers keep on falling off a table, without even the promise of an asymptote toward the end of the series:
The book has a few pages on immigration policy, but no serious discussion of how scalable the Finnish model might be. Surely that matters for judging a utopia?
And that is my review, of both the book and the country.