I use JOSM or Basecamp for this. With JOSM the advantage is that it has a whole bunch of layers (satellite images, free topographic sources, OSM layers, Strava etc). You can convert your gpx track into a layer and split it, combine it with other gpx tracks etc. It does not route though but for small sections you can draw a route manually. For very quick editing and routing I use Garmin’s Mapsource but it is very limited compared to Basecamp.