Keep My Unit as an IP or Sell for $200k Tax-Free Before Upgrading?

Hi all,
Looking for some advice from anyone who’s been in a similar situation.

I bought a unit in 2020 for around $350,000, which has been my PPOR. It’s now worth $550–$600k. I’m in a position to upgrade to a family home for roughly $1 million.

I could keep the unit as an investment property while paying the new mortgage relatively comfortably. I’ve always believed in buying and holding as much property as possible, but I’m starting to reconsider.

If I sell the unit now, I can pocket around $200k tax-free since it was my PPOR before moving. My concern is that if I keep it and sell in the future, I’ll face a significant capital gains tax.

Would it make more sense to sell the unit, put the cash into my new property’s offset account for a while, and then later invest in a property with more land and better long-term growth potential?

TLDR: Upgrading to a $1m home — should I keep my current unit as a rental or sell now for $200k tax-free and reinvest later?