I am currently working in H1B status in Michigan, very close to the Canadian border.
Is it ok if I rent a house in Canada and then commute to Michigan for work every morning? Would an H1B amendment be needed?
Yes, you can reside in Canada and commute everyday to Michigan. There is no restriction.
I hope you understand that you will need some kind Canadian visa too to enter and stay in Canada.
You might also have to file Canadian Taxes that they impose on residents along with Income taxes in US.