Shower Venue ideas

I'm looking for ideas for a shower venue in the city and was hoping a Chowhounder might have some suggestions. There's no budget determined at the moment, which I know can be annoying. But I have other requirements so I'm hoping maybe the other things can be addressed with a "reasonable budget" guideline, meaning not someplace like Spiaggia or other fancier restaurants or venues with huge event fees.

I'm looking for a place for about 25-30 people that is a little more of a blank slate that I can decorate in a more involved way. I would like to be able to bring in linens, florals/table decor, maybe have the flexibility to hang things on the wall or something like that. I had my own bridal shower at Ba Ba Reeba which was awesome, but is so stylized that it's hard to decorate around, so I'm thinking about either restaurants with private rooms that are more plain/clean/stark in feel, OR non-restaurant venues that fit this description where we can bring in catering.

Other than that, the only other "requirement" is that it be well suited for a shower - tabled seating, but enough room to have a table for presents and walk around/mingle. If it was at a restaurant, I think the option of having more family style or small plates would be ideal, but not a necessity. Timing-wise, it would likely be held on a Saturday early afternoon. And location-wise, I'd prefer closer to downtown - north/northwest/west sides are all fine (so, the loop north up to Lincoln Park or Lakeview, west to West Loop, northwest to Logan Square to give an idea of neighborhoods)

I've searched around, but it's hard without hearing from people with personal experience to determine what spaces offer the decorating flexibility outside of the bigger wedding venues.

Any ideas would be very welcome! Thanks in advance!