Congratulations on being a millionaire. You can retire at 55 provided you move to cheaper home. If you sell your condo and move to a HDB 4 room flat, assuming you have children still staying with you, after putting aside CPF SA and MA and purchase of flat ($400k), you will have investable assets of $1.3m. Invest in a 5% REITs portfolio and you get $65k pa in dividends.

This would suffice for a retired couple who doesn't drive, drink, smoke nor gamble. Also by then your children are working and can feed themselves. They may also give you some allowance which you can save.

When your kids are married and move into their own hdb BTO flat, you then sell away your hdb flat and buy a one bedroom condo near an MRT station.