We're in the process of migrating to a new Salesforce org (long story, largely due to person accounts...). I've moved across all the metadata using the force.com migration tool, so the new org is ready to receive our data. This is the first migration I've been involved in and I'm not quite sure how to proceed from here.
My plan was to implement a read-only period in the old org, where users could view existing records but not edit/create any records (it's a quiet time of year so this isn't too much of a problem). During this period I planned to transfer over all the data to the new org. Once complete, I planned to switch all the users over to the new org, where the data would be waiting for them.
After speaking to Salesforce support it seems that transferring user licences to the new org can take up to 30 days. So I'm not sure what to do during this period - users wouldn't be able to log in to the new org because the licences haven't been transferred across. But I also don't want them editing/creating data in the old org, as this would require migrating the data across again.
Could Salesforce temporarily grant us additional licences in the new org, so that users can log in to the new org before the licence transfer is complete? I feel like this would solve the problem, but haven't been able to get a clear answer on this from support.
Or am I going about this completely the wrong way? Does it make sense to do things in the order of 1) implement read-only period 2) migrate data 3) users log in to the new org. How is this element of the migration process usually handled?
We're a non-profit so don't have much budget for this, I feel like I'm almost there but just can't quite work out how to handle the timings - any help very much appreciated!