That's a long enough time horizon where normally folks might say to just park it in an S&P ETF. But, given that markets have run up recently, and interest rates are rising in the short term -- probably just buy up Treasuries directly, and get over 5% in the relative short term. I don't know if you're subject to state taxes, but Treasuries are state tax exempt of course. Then see what the markets do in the next couple years?
As far as I can remember, there's been only one losing decade (00-09) on the S&P in a very, very long time (if ever?). And, a high yield savings account (or Treasuries) will be adding earned income atop your existing income.
That's just an awfully long time to be betting you'll beat S&P returns.