Unusably small ledger columns in HiDPI

[Adam Powell]

Hello,

I've been a GnuCash user for about fifteen years, and recently migrated to
a laptop with a 4K screen.  I just opened GnuCash, and it seems there's a
maximum size on some of the ledger columns which is unusable small.  It
only fits five numbers into the Balance column, and two in Deposit and
Withdrawal!  When I try to move the boundary between columns, it snaps back.

Am I missing an option which would let me do this so I can see my
transactions?

This is with GnuCash 2.6.12-1 on Ubuntu 16.04.

Thanks,
Adam