If they say the $$ is non-refundable, it is probably because they had to pay the venue to reserve your food and lodging for the weekend. They may or may not be able to get credit for your unused space, but it is certainly worth an ask. They might have a late registrant who could slide into the space.
I agree with the others about waiting. You are in a better place to have a positive experience if BOTH of you go with a willing mindset.
