Since a shortage of clamps was the original problem --
Once the steamed and bent gunwale for one side has cooled and dried -- a day or three, depending -- the clamps can be removed. The clamps can then be put to work bending the gunwale for the other side.
The first bent gunwale will hold its shape -- steam bending creates a permanent bend. The small bit of springback, should not interfere with installation days or weeks later, when the second gunwale is ready, if your preference is to install both at the same time. This slows the project down a negligible amount of time, but canoe restoration is generally not a project that has a rush schedule.