Deluge has this nice plugin called scheduler that let’s you program at which time the torrents should download/seed, if you have a small homeserver on something such as a raspberry pi you can just schedule deluge to work when you’re asleep, this way you can seed/download while not impacting your bandwidth when you need it, very useful to really slow connections (like mine).
This way you can keep seeding for months without even noticing!
I guess it varies between ISPs but mine has written to me a couple of times in the past to give me “gentle reminders” not to download “vast quantities of data” during peak hours. :P