Depending on choices from ME1, ME2, ME3, is it possible to have only two remaining squad members to select from for the final ME3 mission?
I don't believe this is possible, even without DLC. Hidden for possible spoilers:
You can avoid adding the Virmire survivor to your party, and it's possible for Garrus and Tali to die in ME2 (and Tali can die in ME3 as well), but I don't think there is any way to get rid of Liara, James, and EDI. You should always have at least those three.