Sony's proprietary speaker wire connectors

[Rike255]

What do people do about these little problems? Someone asked me what they can do and I didn't know what to tell them.
Some Sony receivers come with these proprietary ends on the speaker cables to connect to the receiver. But if someone needs longer speaker wire, or wants to upgrade their wire, what are they supposed to do?

I told him he can probably cut off the ends of the supplied cables, and splice them to some longer, maybe thicker cables. Is that a bad idea?

My other question is, in doing this, is it reducing the impedance of the overall cable? Say the supplied Sony cable is 22AWG and I chop off the end and splice it to 16AWG cable. Will that help or hinder?

Thanks.