Hi RA,
I Run Win 10 Pro on a 3 year old Dell with an i7 laptop processor
I don't believe that Updates are that cleverly controlled. When I updated to 1703 it failed, no reason just went belly up. Having tried and failed a second time I looked back through the update history and found a failed update which I reinstalled and then 1703 installed without problem, this was many months ago when 1703 was first offered. At the end of many attempts by UPDATE to install 1709 there was a progressive list of 1709 needs a restart messages in Update History.
An Update / Upgrade install of 1709 on 1703 existing may well notify a too small partition but if a clean install on a newly formed partition manages to generate *48GB of OLD (where did it come from), on a new partition which now takes 33GB of space and includes Office 2010 Pro Plus and another 10 items of Software (No Data Files) how big can the OLD and Rollback Folders become from about *90GB Windows 1703 with about 90 software programs that I installed, not counting Ms items like Silverlight and Visual Studio etc ?
* REMEMBER:- No data files as everything normally found in USER has been redirected to another partition