People in this forum are mostly from northern India and Pakistan. So, they center their thoughts on the happenings of the then NW of india. But, if someone truly studies the history of Bengal, how it came under the British, who were the locals that supported the British and who are those people that received all kinds of privileges from the British at the expense of their neighbouring community, one will quickly understand that the privileged class was the Bangali Hindus and the underprivileged were the Muslims of Bengal.
The Muslims of Bengal dominated the politics of eastern India for about six centuries. But, in the first half century of Hindu/British Raj, the Muslims were turned into a bunch of landless peasants. Since the British took away power from the Muslims in Bengal and this province first came under the British rule, therefore, the Muslims had to bear all the disadvantages of colonialism. But, this colonialism was supported by the local Bangali Hindus.
To amend the situation, the Muslim leaders of Bengal and other provinces demanded to divide Bengal into two. East Bengal was united with Assam in 1905 and the new Province was named East Bengal-Assam Province with Dhaka as Capital. However, due to continuous opposition by the elite Bangali Babus of Calcutta, east Bengal was again joined with the west in 1910. British were so tired of the Cacutta elites that they moved the central Capital from Calcutta to Delhi immediately after that.
It was a tremendous blow against the Muslims of Bengal who wanted self-improvements, and for this they needed a Province where they would have more power. THE SEED OF PAKISTAN WAS SOWN AT THAT JUNCTURE OF HISTORY. North Indian people always say about Muslim League and Mr. Jinnah, but they do not probably know that the ML was formed in Dhaka by all the Muslim leaders of then India at a convention called by Nawab Salimullah of Dhaka.
You have said about the election history of 1946, it was this vote of Bangali Muslims that again strengthened the ML concept of Pakistan. Therefore, I think, even 60 years after 1947, the reasons responsible for the partition would still have been in place in Bengal. Therefore, a Pakistan (read, a separate Muslim country) would have been created at least in this part of India.