I don't want to get into too many hypothetical scenarios, Raoul, but
doesn't it make sense that [sometime in
the future] a shuttle launch team "may"
spot some trouble involving the tiles
on one of the remaining shuttles after it has safely reached LEO on its way to
the ISS?
What would they do?
They should let it dock with the ISS.
After docking, an astronaut from the ISS, or the shuttle, would take a spacewalk to examine the tiles.
If he/she spots one or many tiles missing in a critical area, there are two possibilities.
[One] Leave the shuttle docked with, and its crew left onboard the ISS, until a Progress supply-ship could bring up repair materials [and a temporary power-pack to take the place of the drained fuel-cells].

[Two] Send up another shuttle as
quickly as possible to bring the
'stranded' shuttle crew home, as
well as repair the damaged shuttle
docked with the station.

Jacob