Bumping into max row size of 65k craft_content table in MySQL 5.5
I came into a similar problem with rich text areas and front end form submissions maxing out memory very easily. It may not solve your issue at the root but as you asked for any thoughts ideas or hacks and for the issue you state. In the rich text field options at the bottom you can change "column type" to "medium editor" which bumps storage from 64K to 4GB. 


Hope that helps in any slight way, sorry if it's off point.