Restoring a backup file (*.tsbak) into your DR environment won't update the licensing information. Licensing is stored in "trusted storage" so the DR environment should keep the same renewal date and won't be impacted at all.
In regards to taking a backup file, starting with version 2018.2.x it's no longer an all or nothing scenario when you take a backup file. But since you'll be upgrading to 2018.1.x that would be the case. But really anytime you're taking a backup file from one environment and restoring it to another, the --no-config option should be used. The backup file has 3 major parts: copy of the postgres database, extract files, and the settings(yml) files. When you restore with --no-config it's really the yml files you're leaving behind which is actually what you want since it's just the workbooks contained in the postgres database and your existing extract files that you want restored. Your other environment will have different IP addresses, etc so unless you're doing an *in place* upgrade, you want to use --no-config.