Tips Bringing Groceries Upstairs?

So both my parents are getting much older and are starting to have more issues with their bones and muscles and we bring in a lot of groceries since we are a family of 4-5. We live in a apartment on the 2nd floor but the problem is since we have so many groceries (costco sizes btw) we have a hard time bringing everything upstairs and there isnt an elevator either. And sometimes my sister and I arent home to help. Does anyone have any tips or recommendations for things i can get to make it easier on them and us?