I doubt anyone has a solid timeline. Signifcant progress in the courts this year is possible, more likely to drag into early next year. Enforcing a favorable judgement, if possible, could drag on for years. The Citgo/Rosneft deal appears to be under CFIUS review and this may affect timelines. It will need presidential approval and who knows how Trump will behave where Russia is involved - and perhaps Pence will be president at that time.

VZ default will likely be disaster for all concerned, particularly us, and on a purely economic basis is not likely before the presidential election in 2018.

Violent regime change in VZ is the most likely disruption to all this.

My guess, fwiw, come back in 6 months and ask again.