You might also consider using dual enrollment, online schooling, or both as resources for the secondary years, whether in homeschooling or brick & mortar. A number of states (e.g., CA, MA, WA, to name a few from different quadrants of the USA) have programs specifically allowing high schoolers to dual enroll in community colleges, with varying levels of guaranteed transfer or admission with advanced standing into the state university system.
Here's a nice starting point for researching state-by-state policies:
https://www.ecs.org/dual-concurrent-enrollment-state-profiles/Dual enrollment is not a perfect solution, either, but it can be an additional tool for some.
