I have a similar issue. I want to collect data from several locations and potentially also control some relays remotely. Some locations (Haiti0 will need to use a SIM card to send data. So I am looking for a reliable cloud based system to collect data and possibly control.
I stumbled on this http://developers.sensetecnic.com/ , which is free. Lets you store, view data privately, and they host node-red so you can run rules and notifications or send data anywhere. It seems like a great offering but for some reason there is not that many people using it.
The other thing i though about was having the remote locations post the data to dweet.io and then I could retieve from any machine i decide to be the central server. you can also do this privately for a few buck a month. If your channel resembles MQTT then you can run node-red locally and from there do formal MQTT or just a serial connection to any controller or board.
I am still just testing different things. Amazon started their IoT offering yesterday which is currently free.