I have never done that but, I would caution that if you are getting a replacement device with the same amount of storage or more storage, your backups are going to be larger in the future anyway. If you sync messages, documents, reminders, and notes with iCloud, those take up space as well. If you use iCloud Photos and you have a lot of photos, that can take up really large amounts of storage.
IF you need the storage for the backup now, you will need it in the future as well unless you are going to a smaller capacity device in which case you would lose data because you wouldn’t be able to restore the larger backup to the smaller capacity device.