The second half of "Blindspot" Season 2 will likely reveal a new informant for Sandstorm. Series creator Martin Gero said not to count the group out just yet, since they will still manage to stay on top of the FBI.
Dr. Borden may no longer be with the FBI when "Blindspot" Season 2 returns. This does not mean though, that Sandstorm will not continue with their mission. The group will likely find a replacement informant, who can feed them information about the FBI.
Showrunner Martin Gero said that the midseason episodes in "Blindspot" Season 2, will bring Sandstorm back on course with their mission. They somehow manage to stay on top of the FBI, even without Jane Doe and Dr. Borden's intel. It is likely that they find a new ally from the FBI, who becomes their new mole inside.
"Somehow they always stay a step up ahead of us and it starts to drive us crazy trying to figure out how they are able to anticipate our moves," Gero told Entertainment Weekly.
It is clear from Gero's statement that Sandstorm will remain under the FBI's radar when "Blindspot" Season 2 returns. The covert organization will remain a threat to the government and to the country. They will continue to execute their plans, with or without a new source of intel.
However, speculations are rife that Kurt Weller could be a covert Sandstorm operative. This would explain why Shepherd protected him in the Season 1 Finale and why Sandstorm has been keeping an eye on him. It would also explain why Jane has Kurt's name tattooed on her back.
Regardless of what happens in "Blindspot" Season 2, it is clear Sandstorm is not going anywhere. The second half of the season may open with the group going underground, but this is likely only temporary. As soon as they find a new mole, Sandstorm can quickly pick up where they left off with their plans.