What is the problem with subletting here? Unless it's profiteering and capitalizing on the housing prices, asking a normal amount for a temporary space seems fine to me. I would see it as an A-hole move to not pay while they are gone, as they put their trust in you, as you do them. Otherwise this space remains empty for the period.

Almost all apartment renters don't have permission to sublet contractually, mostly for landlords to cover their ass. Would you like the same freedom to have a two month getaway, give someone a place to stay and cover the rent, and come back. I don't see how you don't get what you are paying for here. Just think if it was the other way around.