I have a fantasy for a Torchwood relaunch.
The Doctor pops into the reactor control room right before Owen’s body is destroyed, gets him out of there. And maybe through some Time Lord superscience properly fixes him(or not- though I think involving the Sisterhood of Karn might have the right feel for Torchwood). Moffatt is on record as being against The Doctor showing up on Torchwood.. but he’s also on record as not wanting to bring The Master back. Moffatt lies, and can be overruled by BBC execs even when he’s being honest.
Then, perhaps, wanting to give Tosh a proper burial, Owen tries to locate her remains. Reviewing reports about the explosion, there’s no sign that her remains were recovered and no detection of her DNA at the site to indicate obliteration. Her body is gone. Owen hypothesizes that it was thrown via the rift to somewhere else, launches a search, gets Jack and Gwen back in the game to help… then they find her, alive due to some combo of rift weirdness and/or Jacks blood(which is known to have regenerative properties in normal humans).
With the team back together, a proper Season 3 can begin.
Ianto is probably gone, reversing all deaths just wouldn’t be Torchwood and his had the strongest emotional impact on the team. It would undercut too much of what happened in the aftermath. Though teasing with an apparent return or a Pet Semetary type “resurrection” story might have potential.