Aliment depends on how dependant your wife is financially and what resources are available. There is no legal reason for either party to move out unless there is abusive behaviour. Aliment is only paid during the period of separation and periodic allowances are sometimes paid for three years max after divorce to allow for readjustment. After a short marriage readjustment may be considerably shorter than after a shorter one.
That means if aliment/periodic allowance is a possibility it can be for a shorter term if the finances and divorce are agreed quickly.