We used a different exchange company for our purchase over here, on recommendations that we should employ someone giving us 'personal management' for such a large transaction. To be honest, although we had used Transferwise for smaller cash movements in the past, we didn't think they would deal with something this substantial.....big mistake! Although the company we used were very professional, and worked flexibly around a last minute bank hitch, their rate was a few fractions of a percent lower than Transferwise, costing us several thousand pounds. Transferwise do, we now know, handle larger transactions. Everything since has been via transferwise, car buying etc, and they have been faultless. Not sure if this helps you, but I'm sure others will chip in! Good luck with it all!