Update: Redid the game from much older saves, before I opened the third elemental portal, and I had six unused Bloodstones (15 total stones). I chose Ice portal instead of Fire, did not kill Cassandra, and made sure I talked to the main Homestead NPCs (Zixzax, Icara, Weaver of Time), then ported out, ported back to End of Time, then used another Bloodstone in the normal world, THEN ported back to End of Time.
This procedure, or something in the above, seems to have worked. I now have all portals open, except the Forbidden Portal, and I am off to go kill Cassandra, after I redo some crafting.
