Buffalo says 30 days for TRV processing of mail in applications. 30 days is today. With Canada post delay, this may be more. Try e-mailing the buffalo office after a couple of weeks (around 5-6 of July), they usually provide responses within 24 hours. Ask them if you can send a representative to pick up your passports.
Before sending email to buffalo, do this: http://www.canadainternational.gc.ca/buffalo/imm/contact-contactez.aspx - temporary mailing instructions to receive your passports back. Do that asap.
My 2 cents: No, you have no options but to wait. If no one is present at the office when applying for TRV, it is considered as a mail-in application. Mail in applications go through a different process flow compared to in person. As advised by the site, you should have sent it 3 months before your travel date, in your case April. The mail in applications are getting super delayed, and with the added mess from Canada Post not working, it is even worse.
You still have time though. Wait for another month and if it is still delayed, change your tickets! (99% you should get it by then)