Try it and you will get your answer.
it should be possible right, i doubt you will consume the FUP of 1GB on your 2 hour skype session.
well the main thing is here is if your signal / connection/ location / traffic can handle your skype session.
will it be enough to handle the latency and bandwidth required by skype? let us know.
Yes, 1GB can at least handle a non-HD Call for about an hour or two. However, as said signal and slow internet (congestion) might affect your overall expirience.