The gotta have core quiver, imo, is one gasser and one charcoal grill. A second charcoal cooker is a nice to have.
Your one charcoal cooker could be a kettle, a Summit charcoal, a PK, a gravity feed, a WSM, a UDS, a BGE, an offset. In terms of function, the Summit pretty much obsoletes the kettle, unless your kettle is going to be used for big party capacity, roti, pizza or other niche specialty uses.
Go ahead and keep the new kettle if you have space for it and see what you use.
As the posts above mostly indicate, you will probably not use the kettle much. Especially since you live in the great white north, the Summit is going to be >>>> than the kettle for year round use.