No reason to worry about the tunnels or the bridges below Croton. Those would never get catenary. The extra cost would never be justified and the NIMBYs are going to be too strong against the poles messing up their views of the Hudson. North of Croton is much easier, but it is really dependent on the state whether it wants to pony up the money for the catenary and realistically I do not see it. It is a lot of wire to justify it up to Poughkeepsie or Albany. Diesels it will be for my and your lifetime. The diesels will probably get some Tesla like batteries to address the gaping issue across switches, but wire ... I do not see it.