I hear you, and you're not the first to point out that the CPI isn't an accurate measure of their expenses.

I looked at Shadow Stats a while back and didn't find them convincing. However, it's very clear that the CPI isn't intended to be an accurate depiction of what any given person or family will spend.

For example, if you have a paid-off home, your personal inflation will be unaffected by interest rates, rents, etc.

I think your plan to live half the year where costs are lower and where you'll enjoy the new scenery is an interesting and potentially great thing. However, as you alluded to, it may not be so simple, especially as you age.