The Summer Camp respite fund for Autism Ontario is open and parents can apply until June 2nd.
It's not a huge amount of money (usually a max of $ 500 per child), but it can help. It's a random draw, so there's no guarantee or triage process.
One note though: even if you're rejected, save your receipts from any activities your child does over the summer (including therapy and respite as well as camp). Sometimes the money doesn't all get claimed and they'll do a second draw in October.