Resilio Sync
https://www.resilio.com/individuals/Cross platform. The paid version (pay once, activate on as many devices as you want) lets you have encrypted shares which allow you to have a P2P cloud of encrypted data on clients you don't trust, and decrypted data on clients you trust, all with read/write permissions and network scheduling and all that. Save the secret otherwise your data is gone, though.
I run Sync across all my devices and it's great, except the phone apps don't run in the background. I'll volunteer to host for you (like Crashplan! hello again) if you tell me how much space you need. You have to install Sync on all your devices.
https://stablebit.com/CloudDriveI'm a huge fan of Stablebit's stuff. This does encrypted storage to cloud providers very well. Licensing is per-machine. Windows only.
http://www.division-m.com/cloudxtender/Cloudxtender is by Division-M and their code quality is generally a bit worse in my experience but still workable. Windows only.
Duplicati
https://github.com/duplicati/duplicatiEncrypted chunked backups that let you save to the cloud.
All of these involve encryption that's unlocked forever per device, not by entering a password every time. For that you might need something else (or maybe you could host an encrypted container?)