I'm a PG user in a big corp with an IT dept that administers a PG server/instance that I use. It's an old install, v11.5, and we need to upgrade to v15.3. They want to bring the upgraded DB up on a new linux vm which has OS upgrades of its own. So it's a move AND an upgrade.
Have them upgrade the current server to 11.22. It's trivially easy, with only a few minutes of down time.
Remember (and tell your IT dept) that PG point releases do not add new features: only bug fixes. That means point releases aren't nearly as risky as other products.