My passport expired last week. Since I'm getting married in June, it was recommended that I renew after my name change. However, my uncle passed away today in the USA. Is there any way I can enter the US with my expired passport?
You can try. The US border agent has the option of declining to admit you. The more recently your passport expired, the more likely you are to be allowed in. Other current ID will certainly be required. Note that it is very unlikely that you will be able to fly into the US with an expired passport; land crossings are your best bet.
Canada does permit rush passport processing, and if you live in a city with a passport office, you may be able to get your passport by the end of the next business day, but evidence of urgency is required plus payment of a significant additional fee: https://www.canada.ca/en/immigration-refugees-citizenship/services/canadian-passports/urgent-emergency-passport.html