OliverB360 :
LGA2011-3 is going to be the same size as LGA2011?
http://www.tomshardware.com/answers/id-1976870/lga-2011-backwards-compatible.html
This thread suggests that the LGA 2011, and LGA 2011-3 socket are physically the same size where dimensions are concerned. I can presume since there's no significant changes in size, only functionality, that a cooler designed for LGA 2011 should fit just fine.
If this were not the case you'd probably see a flood of LGA 2011-3 compatible coolers hit the market by now. The old 2011 socket CPUs didn't ship with stock coolers, so I can't imagine the new 2011-3 socket CPUs will either.
In any case since you've said you're recycling the H100i from another build, so what do you have to lose by...