Before going away on holiday I decided that it would be nice to get a longer prime to give me a little more reach while away.
I decided to get the Panasonic 42.5mm f1.7. The fast aperture and reach of the lens proved very useful in allowing me to get pictures that would have been impractical with just the wide glass. I was also very impressed with the Power O.I.S. which worked will with the on sensor stabilisation of the GX80.
While I think taking the 42.5mm away as the only bit of glass would perhaps be a little risky it is a great partner to a wide prime.