Don’t worry, it’s entirely possible to throttle a fiber connection down to the speed of DSL on 60’s copper right at the edge of the DSLAM’s range, and that’s a service we’ll be proud to provide, since our customers expect nothing less of us!
(More realistically, a number of telcos, in areas where they aren’t interested in buildout, are just handing off the ISP side entirely to the local cable monopoly(since they already have the coax, and DSL generally can’t catch DOCSIS without actual infrastructure upgrades) and upselling people on cellphones as hard as possible. New York has been wrangling with Verizon about their plan to do that in a number of hurricane-hit areas lately)