Decison time on a postdoc offer while applying for other positions

I have applied for several postdoctoral and one lecturing positions recently. A week ago I had an interview for one of the postdoctoral positions and I should know the outcome of this interview by the end of next week. During the interview I was asked if I was applying for other positions, to which I said yes and briefly described what these were.

The project is a very interesting one but I also want to consider the other positions I applied for (especially the lecturing one) if I were to be the preferred candidate. However, I will have to wait until the end of February or so to hear about these other positions.

So, if I was chosen for this postodc I was interviewed for, I was wondering how long it is acceptable/customary to make them wait until I give them a final response.

I'm sure they would be ok with a couple of weeks, 1. because moving overseas can be a bit of a change from a personal perspective and 2. because considering other potentially interesting opportunities makes sense at this stage in my career, but I was wondering if making them wait for a month or so was too long.That being said, I heard about people making an employer wait four months or so but I would find it rather impolite.

Thanks for your input!