I've just done this (buying from a TP forum member), I bought X-H1+Grip with two extra batteries, sold the grip and my X-T2 (less than £400!!!) and the upgrade to the X-H1 + 2 x S batteries stands me at £200, IMO well worth it just for IBIS and the higher res EVF alone.
Two many people on this thread are looking at the value of their cameras rather than the cost of change. As I've said before, the cost of change X-T2 -> X-T3 is pretty much what it was on the day of X-T3 release, and other 'upgrades' X-T1 -> X-T2 or X-T2 -> X-H1 are considerable less than they would have been on day of release. There is some great gear out there at great prices, just decide what you want and buy it!!!