Ukraine is huge and has loads of track and trains that gauge, so do Lithuania, Latvia, Estonia, Moldova. There’s even a ukrainian-gauge line running west to Katowice, could make sense to extend it, and make another to Gdansk. Otoh a transversal standard-gauge line connecting Romania to Poland via Chernivtsi and Lviv could also make sense.
Western europe should welcome the technical expertise of Ukraine and Belarus railways, they move a lot, efficiently.
Hey, not so long ago, there was even talk of a canal linking the Dnipro to the Wisla, recreating the old ‘viking rus’ trade-route (although have to consider also impact on wetlands… I recall used to sit next to the IPCC rep from Belarus - he was passionate about methane emissions from wetlands - but suffered from politics …)
This makes sense for mid-latitudes, but the timing of peak power will depend on how much energy the current youth in India and children in central Africa will aspire to use as they get older. That’s hard to ‘predict’ - it’s their choice of development pathway, but hope they don’t follow China’s route with so much cement, steel, roads, there are other options.