I don't even have a suggestion of how you can get a 75,000 item list and SharePoint to play nice in this scenario. I have a customer with 33,000 records and we found clever ways for him to make it work but for you, trying to go offline, I don't have even a good suggestion.
What about moving to CDS as a data source since you don't have SQL available? That is where I would point you to look for a better, more scalable solution.
I was afraid you would say that. I'm going to leave this post up to see if any other community users have found a work around.
My initial work and investigation found 'code' to bring records into the collection in 500 record chunks; however, the 'code' was developed for a connection to a SQL database. I ran into another issue with the code when using a SharePoint datasource and the dreaded 'service limitation' error but found a work around fro that.
Do you know:
If there are any plans to modify things to remove some of the service limitation when working with SharePoint?
The thought process around not letting a user pull in a range of records?
I understand the number of records limitation but it just seems odd to not have, what appears to me, simple selective parameters to bring in a range of records.