Where else other than Jagannath Puri, is the worship of combined deities of "Krishna, Balarama, and Subhadra" done? i.e., any other temples such as the Puri Jagannath temple?
From the official website of Shree Jagannath Temple:
Jagannatha is not the only deity worshipped in the temple, though it is known as the 'Jagannatha Temple'. But along with Jagannatha, two others namely, Balabhadra, and Subhadra are also worshipped here. These three, constitute the basic and fundamental Trinity and are considered to be the forms and manifestations of the omni-present, omni-scient and omni-potent supreme power. Sudarsan who is supposed to be the fourth important divine manifestation is also worshipped with the celebrated trio and these four are known as the Caturdha murti or the four-fold divine images. Besides, Madhava, a replica of Jagannatha, Sridevi and Bhudevi are also installed in the sanctum sanctorum and worshipped.