Obito explicitly confirmed it now, and it has been hinted at earlier as well. In the past, Obito complained how "Nagato wasted the Gedo Rinne Tensei", and that would suggest that this technique can be used once in a long period at the very least. Now we have confirmation that it can only be used once since it consumes the user's own life in the process. As for Nagato, he supposedly could have survived using it as Konan hinted, but it would be due to his Uzumaki lineage, known for super strong life force. Maybe it was the reason for Madara choosing him in the first place. I think this will be revealed in the subsequent chapters, along with Naruto finding out that Nagato was his relative.
I think that the fact that this technique can only bring back people after a short period of time should be mentioned. I have two things, that I think is proof that there's a time limit on this technique: Nagato said himself, that there's still time. Why would he say that if he could resurrect the people back any time he wanted? Also, what about Yahiko, he could have used this technique to resurrect him, but he didn't. The only time limit mentioned was how long Nagato has left before he would die which coincides with Konan's remark about how Nagato would die if he used Rinne Tensei with his chakra levels at the time. Remember he was meant to bring back Madara, who was likely dead way longer than Yahiko.
Obito, and Madara both stated Nagato could of used the technique on either of them. So there is no time limit.It is hinted to rely on the chakra level of the person and mastery of the Rinnegan. So when the ten tails is complete Madara will want Obito to use Outer Path: Samsara of Heavenly Life Technique to revive him so he can become the jinchuuriki.
Because Obito is fighting using his chakra like Nagato was, Obito should die really if he doesnt rest and get his chakra back so Madara and Obito need to wipe out the alliance army before Obito revives madara.Now thats a problem beause if there a no shinobi left whats the point of infinite tsukuyomi.And if they don't wipe out the army and Obito doesn't rest he will die after using the technique to revive Madara.If Obito dies then he doesn't get to see Rin in the dream world, Obito wants to see Rin above all else so i cant see Obito dying just for Madara.