Copying database content when upgrading site via copy to new server?

I'm about to do a long overdue upgrade (from 0.9.6.3 to 1.0.5) by copying the existing site to a new server, performing the upgrade there, and then pointing the website hostname at the new server.

I'd like to minimise the period during which site users are unable to edit their content. There is always the risk that the upgrade on the new server doesn't go entirely smoothly, and it might take me a while to sort out.

I'm assuming that once I've copied the existing MODx database to the new server, I won't be able to 'refresh' the site content (on the new server) again from the old server, so once I've copied the data, I will need to lock out the users on the old site to stop them from trying to make any subsequent changes, or will I?

When I upgrade MODx on the new server, does the upgrade process actually make any changes to the database?

I'm wondering whether, once I have upgraded the new server, I would be able to reimport the site content on the new server (is this just the modx_site_content table, my users can't edit chunks, snippets, etc?) or would this not work as expected?

If this is not possible, I'll just have to let users know that there will be a period after which they will not be able to edit content on the old server, and will not be able to make any further changes, until I have got the new server running properly, but they will of course grumble about this..