1) Realise after 10 minutes of fiddling about that you can't do this with the iOS contacts app.
2) Research on the web and discover that either you use (a)the Mac Contacts app or (b)the iCloud web interface.
3) As you are travelling iPad only, you choose (b)the iCloud web interface and open iCloud in Safari.
4) Find you can't get the iCloud web page in Safari but only this:
5) Download the Chrome Browser onto your iPad but find it's the same - no iCloud home web page.
6) Download the Dolphin Browser onto you iPad
7) Select Desktop mode in settings to emulate a non iPad browser and go to iCloud.com
8) Finally get to this page:
9) After a small celebration, select contacts, select the '+' icon to create a new group only to find it's not working on this web render.
10) Give up. Resolve not to travel without your laptop again.
Shabby Apple, really shabby.