Welcome aboard. 2 to 3 weeks at temp 18 degrees or higher will be fine in sampling a few. Is the IPA a kit brew? If so 6 to 8 weeks allows for a bit of nice maturing. For best results ferment for 2 weeks.
Running two fermenters, a week apart, is a good way to build up stock whilst still enjoying some of your nice brew.
A good thing to do is sample a few bottles at 2, 3, 4, 6, 8 weeks to note the difference and improvement, then settle on what’s best for you.
Cheers.