I guess Finestre as alternative would serve. Mortirolo would be similar to 2012/2017 ish?Regarding the plan B for the two big stages:
- for stage 18 it seems the plan B would be doing Tonale - Aprica - Mortirolo (unclear which side - a local article even implied the one from Trivigno, never used...), then up the valley until Bormio and the final climb.
- for stage 20 today a local article claimed that the plan B is to have Finestre, and that RCS is already seriously considering it, possibly because it needs some minor roadworks to be passable, so they need to commit asap.
Needless to say, stage 20 has the huge problem of passing through another country, with all the administrative issues that may happen in case of the necessity of clearing snow, AND the fact that any plan B that doesn't include Finestre would look like a medium mountain stage.