> we **really** need cell measures within Iris

Absolutely. I *heartily* agree!

> Forcing users to use the netCDF4 module is just ... :punch::nose:, resulting in :goberserk:

Don't forget this PR is useful in its own right and doesn't force anyone to do anything. *You* might need to use the netCDF4 module to access the specific data you're working with, but someone else might be able to use this regrid routine without needed access to cell measures at all. For example, regridding a high resolution rotated pole dataset to a low resolution non-rotated grid.