No, he cannot survive an assault from all five Kages at once. Dealing with Gaara's sand will prove difficult, especially when inside Susanoo (considering Gaara has the feat of pulling Madara out after his sand was made lighter). Ay typically cannot be caught by Sharingan genjutsu, and has canonically avoided Amaterasu. Mei isn't really a factor here but her mere presence will just give Itachi another thing to think about; Tsunade will be immensely useful in healing any members who were unfortunate enough to receive damage from the Uchiha. If Onoki's super Jinton comes out, it's over. This is assuming that both sides possess knowledge; w/o, the Gokage would still take the win but with more casualties.
