Offset or not spreadsheet

Hi all

After helping out a fellow MSEer who PMed me for some help with my original Offset or not spreadsheet which is here , it was apparent that tax free ISA savings weren't being taken into account. With a couple sticking £6k a year into them it has a huge bearing on your breakeven point. So, the spreadsheet has been duly expanded to include ISA savings, as well as normal savings, it is indeed now a SPREADsheet, with columns aplenty. Click here for the with ISA version, it's populated with made up figures, adjust it to suit your circumstances.
As ever, don't take this as financial advice etc. I'm pretty sure the formulae all add up, but please let me know of any obvious howlers I may have overlooked after 1 too many glasses of red wine.

Cheers

Youreds! (Cardiff here we come!)