Jack Wikle who is locally famous for mame keeps many hardy trees as houseplants in his basement under lights that never see the light of day. He has Shimpaku, other Junipers, Pines, etc. I'm going to look through my archives for his displays. Here's one from 2019 AABS Show...
Jack at his display in 2013...
Here's a display at the Michigan All State Show of 2014...
Again at 2012 AABS show...
Jack auctioned off his outdoor trees about 5 years ago. Many of his mame trees have been in his care for over 20 years, and one Juniper over 40 years. I'm guessing, but I think that cascade juniper is the 40+ year old critter along with an magazine article about it. I can keep mame for 2 or sometimes 3 years.