I have always planned for the possibility that I might need to migrate to other software.
My LR workflow involves using mostly one main catalog for my 'in progress' work (I sometimes create a special catalog for specific projects, then re-incorporate the data in the main catalog later when I'm done). Whenever I finish a rendering, I export a full resolution, full size, 16-bit per component TIFF file as the 'completed' work into a separate directory tree in the computer's file system. A second LR catalog is used to manage all such completed work—no editing allowed, just search in the Library module and sometimes Print.
All of the files, both original and rendered, (including the LR catalogs and all presets) are backed up to two separate archive drives after every editing/work session.
This way, I always have the unedited original file and the fully rendered, finished work. I link them via file naming conventions so that I can always backtrack from rendered work to original capture, and if I have to move to some other software, I at least have not lost all my editing time. I would move as simply as possible, just the original files unedited but with all metadata included.
So ... You can search in LR for all files that have been edited, export them into 16bit TIFFs, and thus ease the transition to C1 if you so choose.
I strongly recommend this workflow anyway: any parametric, lossless editing system is essentially looking at the original file as an interpretable entity, and the interpretations can (and have!) changed as revisions of LR have surfaced. I always what what I have completed as a revision to stand alone without interpretation so that I can get that exact thing repeatedly, regardless what software I use to view or manage it.