It has a possible to fuck Sandra in next patch ?
No. Next patch is the Abrupt ending. I don't think there is going to be that much sexy time in that one. According to a post on HC's Patreon, the 'Hero Ending' will include a bit a of sexy time with Sandra.
On another note, HC said that the 'Good Ending' will include sexy time with Maya, Harry's childhood friend.
I find this interesting because, if HC intends for the 'Good Ending' to be a good ending for Harry, it might be that Maya will have something to do with it. I made a post before about how interesting it would be for her, the girl who played a major role in his highschool trauma, to be the one to come to his rescue. Then again, it would also be interesting to see her helping Luca corrupt Laura even further. Looking forward to it either way.