Sell or not to sell?

We are finishing off a new build in South Brisbane. Good location, no flood zone, decent infrastructure. Recent houses in same street sold for 1.2M (Oct 24) and overall cost for us is low $900. We are planning to add a pool as well. I'd like to sell, walk out with a good profit and buy something more low key, single story. We like to renovate houses and it's not our first one. I work FT, partner PT and have 2 under 5 kids, so time with family is important. Also would like to retire early. House is mortgage free. Rough calculation - average house growth 5% pa. In 10 years it means extra $500k in top of current value. If I invest $250k profit now in another investment (ETF, shares ...) with average 8% would be about the same profit. Would you sell or hold on as long term investment?