I believe you'll find online that the majority of large single bowl and double bowl sinks offered are 33" wide because most sink base cabinets are 36" wide. You can also find sink base cabinets that are available standard in 30" and 33"

Sink base cabinets larger than 36" in size would most likely be special order or simply custom sized cabinets.

I installed a 45" Kohler Stages Sink as part of my current kitchen remodel. I am putting in new counters so it is a little different then yours. I installed the sink in an ikea 36" cab with the sink spilling over in to the next door 24" cab. I had to cut out apart of the cab walls so it would fit and modify my top drawer on the 24" cab to allow for the sink.

Is it an over counter or under counter sink? An undercounted is going to be more difficult.

You'll need to have a granite fabricator (I am assuming granite countertops) expand the sink cut out.

You need to modify the existing cab and one next to it to fit in the sink. You'll need to cut an opening in the sides of both cabs and modify the drawer layout on the cab next to it. This will be difficult to do with the countertop installed, but it should be possible if you cut the expanded sink cutout first or are able to remove the countertop while working on the project.

Make sure the drain(s) are in the main sink cab or you'll need to make the cab next to it also be used for undersink plumbing, which IMO is wasted space.

I would check with a local countertop fabricator about the project, as everything hinges on expanding the cutout.

Someone recently had a stainless sink custom fabricated. Maybe justmakeit? I'm much better remembering pics than screen names.

That would probably be the easiest option, get a sink made to fit the opening you have. Though I'm not sure why you'd need to replace the sink.