EU passport, same residence. The only rules I can find is 90 days visa free, without any refence to "within 180 days" or similar, which would suggest that the clock resets at every entry.
I checked the ICA pages, but it doesn't really help. There is a mention of "extension of short term visit pass" but that refers to
"submit an application for extension of stay (not more than 89 days from the date of entry) online via e-XTEND." But we'll never be more than 89 days in SIN after the most recent entry.
It's undecided yet whether to stay long term at a hotel (it would probably be only a few checkouts, as my wife would spend more time in SIN) or rent a serviced apartment - at first look they seem to be in the same ballpark pricewise.
If push comes to shove, I can alway relocate to KL after 3 months, but would prefer to stay in SIN for the whole period.
This whole thing will not happen before November, so just checking my options/terms in good time beforehand.