Reference quoted by news articles on the subject on how long it was estimated to take for the C-Lion1 to get repaired. However, you likely have a point, that the mid-Atlantic probably add some % to the on-site repair time and ++ on time to arrive. Much further away than Sweden to Lithuania.

Right, Baltic Sea has considerably shorter distances on average. I imagine weather conditions might change the equation, though, if you need to send icebreakers first to open up some dozens of kilometers of passage. Right now the sea is still open, except for the coastal areas in the very north.[1]

[1] https://en.ilmatieteenlaitos.fi/ice-conditions/