I will be attending a girl’s trip to Chicago. We will be there for five days and are planning an impressive lineup of dinning option. Some of the restaurants we would like to dine at are not available on open table mainly The Girl and the Goat, does anyone know how soon to reserve a table at some of Chicago’s best restaurants?
ASAP. GATG only reserves 3 months in advance on Open Table BUT...you can call them and get a res further out than 3 months.
Most places only take reservations 3 months out and if the restaurant is hot, don't wait a day past that mark to reserve. That said, always call if you can't get a table from Open Table.
I would suggest reserving as soon as your plans come together. It's easy enough to change or cancel a reservation if your plans change.
That being said, the number of places which completely fill up more than a month in advance is extremely small, perhaps no more than a dozen or so. Girl and the Goat happens to be one of them; others include Goosefoot and Topolobampo. Just about anywhere else, you'll find openings as long as you can be flexible; when you're looking for a specific day and time - such as at the 7:30 pm Saturday peak - you may need to reserve further in advance than for a weekday or off-hour.
Opentable gives good insight into how difficult a place is to book. For example, if you look for this coming Saturday (two days from now), you'll see that some places have no availability, and many others have availability only for seatings before 6 pm or after 9 pm. Look for a Saturday 6-8 weeks from now, and the number of places with limited availability is extremely small.
Fortunately, Chicago has a huge number of excellent restaurants, so unless you insist on going to one of the handful of trendy "hot" places, you should be able to find reservations at great places worth considering for your trip.