Thank you guys for the valuable input.
We reckon if we sell both our investment properties right now, we should be able to pocket around $1.8-$2.0m. In return we will have to forgo around $140k of rental income per year.
At the moment, our rental income is more than enough to pay for the mortgage payment for all 3 properties, without even using our CPF.
So if we sell, we could pay off our mortgage of our own stay property and still have around $1m of cash for investment. And if we reinvest to buy a $2m property with $1m loan, we could possibly get a positive income of around $3k per month at most, which is really not that great because by doing so, we will have to pay around $200,000 of stamp duties (3+7% ABSD) and other cost such as reno and agent commission etc
I am not sure if my calculation is correct, but assuming it is, then it doesnt really make much sense for us to cash out.