We've recently implemented a new plan where sites are placed inside different site collections, depending on their purpose.
One of the issues we face is that several team sites (SharePoint Online) were created about a year ago and are currently sat in the wrong site collection. The sites have had a lot of work done to them and contain several GBs worth of data.
Having done a bit of googling I know that you can save a site as a template and deploy it elsewhere. However, the template file has a limit of 50MB, and these sites go well over this if I'm trying to move all the content.
There is also a site manager utility in SharePoint, which can be accessed using "http://yoursite/_layouts/sitemanager.aspx". When I view this tool however, it appears to limit the view to only the current site collection and not all of them.
Does anyone know if it's possible to migrate a site to another site collection? Preferably without having to purchase or use third party tools?
Unfortunately this was the article I'd used when trying this previously. It appears the first method in his guide restricts you to only moving sites within a site collection, not between multiple ones. The other method of saving a site as a template also limits you to a 50MB file, but our sites are several GBs in size.
If the sites are that size then its going to be a case of either recreate and manually move the data or using a third party tool as I don't think any of the native functionality - as you say - is going to cover what you need. Whilst you are considering moving the sites I would also consider, long term, moving to a flat structure as opposed to a hierarchal structure as that is what is recommended by Microsoft going forward for modern sites.