결론

Column
 ㄴ Column
   ㄴ ...
 ㄴ Expanded
   ㄴ SingleChildScrollView
      ㄴ Column

결과물

Code

Widget _buildBody() {
    return Padding(
      padding: EdgeInsets.all(8.0),
      child: Column(
        children: <Widget>[
          Column(
            children: <Widget>[
              ...
            ],
          ),
          Expanded(
              child: SingleChildScrollView(
            child: Column(
              children: <Widget>[
                ...
              ],
            ),
          )),
        ],
      ),
    );
  }