Firstly congratulations on the first opportunity, go out there and wow them, and enjoy it yourself to.
Secondly, yes perhaps just doing the one spot might just get stale over time, same old same old till you get bored playing it, even though the audience request it every night your on.
So taking up a second gig elsewhere could help, (Not at the same venue) Force you to learn new stuff or might not, only you can tell that. However a lot also depends on time, your own and whatever you may have to use for other purposes, such as earning a living at some other skill, I don't know that one of course, but if you finish up getting too physically tired through working too many nights, that can be a slippery slope to disaster. Only you can know the answers to how much time you can give.