The answer is no, it is not possible. Any fixation procedure compromises the integrity of cytoplasmic membrane, which allows dyes such as 7-AAD, propidium iodide or DAPI to enter into the cell. As John recommended, you will need amine reactive fluorescent dyes (check this reference
https://doi.org/10.1002/0471142956.cy0934s53) or acquire your cells immediately after staining with 7-AAD.