Living arrangements after separation

Has anyone been in this situation, and how did it turn out?
Hi ladies & gents,
I am trying to leave my fiancé, father to my two kids aged 4 & 6. No other children involved.
We own a house together. My plan is to move out with the kids to a rental apartment for the time being. The kids will be living with me for the most part, with lots of time with dad when he is home (works out of town in spurts of 2-3 months at a time). He wants to buy me out of the house and stay there (not sure for how long, could be a year, could be forever). My daughter in particular is VERY sentimental and sensitive. I'm worried she will have a hard time with the new living arrangements, having to go back to the "family home" to visit dad and won't want to leave again. Maybe it will be the opposite, and be beneficial for her to be able to go back to that house? Has anyone been in this situation, and what worked the best?