It's unfortunate that the lack of information on this thread may lead some to run with the wrong ball.
Other threads the OP has posted in her former incarnations will reveal that, presupposing they are willing to leave their father, one of her dcs would, by virtue of age and sex, be unable accompany her to a refuge. Another dc would point blank refuse to go and, as that dc is unbelievably also currently living with their father, cannot be compelled to accompany her.
Another dc who is living with the OP is the subject of considerable manipulation by their father and would also no doubt refuse to move yet again if such a move would take them further from him.
No women's refuge that I know of will be able to keep the OP and all of her dc safe as they will not be able to prevent the elder dc from revealing their whereabouts to their father, the OP's abuser, if the OP herself is able to constrain herself from doing so.
If such a refuge were to exist, and were the OP able to enter it with all of her dc, problems would arise when the time came for the OP and her dc to be rehoused. Even if the OP were able to change her name and those of her dc and relocate hundreds of miles away from her abuser, it is improbable that all of the dc would agree to keep and maintain radio silence, as it were.
Indeed, one of her dc has proved capable of considerable deviousness which went some way to sabotage the OP's early efforts to keep herself safe from her abuser and his lack of boundaries. It also gave her abuser opportunity to paint the OP in a less than flattering light to certain agencies and bodies thus gaining him a credibility that has enabled him to gain unfair and wholly undeserved advantage.
It should also be understood that, given the current circumstances, if the OP enters a refuge at this late stage her dc will be irrevocably divided. Some may subsequently add abandonment to the long of list of maltreatment they have suffered during their early years and, as Memoria has said, as adults, turn against the OP for failing to save them when she had opportunity to do so. Any hurt and grievance they may feel would be further compounded were the OP to take her younger dc and, effectively, disappear off the face of the earth.
In addition there is a far more compelling reason why the OP should resist the temptation to take the line of least resistance at the present time which is that there may be opportunity for all of her dc to be reunited under her roof in the very near future.
In order for this to come to pass, the OP will need to draw on the inner strength she undoubtedly possesses, shake off the mental shackles that he used to imprison her and which need no longer bind her, and redress the untruths she has told by accounting for her lack of honesty to those who have the power to help and support her to bring about positive change to her life and the lives of her dc.
For anyone who remains in any doubt that staying put and standing firm is the wrong advice to give this OP, such is the current parlous state of affairs that if the OP were to ask SS to take her remaining dc into care it is probable that they would be placed with their father.