How do I bring in my Strava archive?

Strava lets you download everything you recorded as one archive. On strava.com, open Settings, then My Account. Under Download your account, choose Get Started, then Request download. Strava emails you a download link, which can take a few hours; upload the .zip as it is, without unzipping it, through Manual import. An archive you upload is your own file, so the history it brings in stays in Trailwise when you disconnect Strava. Trailwise offers this step before you disconnect Strava.