Poodles do really like to be close to their people. Lily tends to follow me from room to room as I go about my business in the house. I also get a very happy greeting from her when I get home even from relatively short outings. However she does fine during the day when we are at work. We do have another dog, but honestly I don't think they interact much when we aren't here even though they play together lots when we are out in the yard with them.
I think that foster dogs are under unusual and stressful circumstances (even though I am sure you are doing everything you can to make their stay with you wonderful), so I wouldn't read too much into their behavior in deciding how your own dog would be when you left.
We make sure our exits from the house are low key. If the dogs are in other rooms when we walk out, we just leave. If they are near the door, we just say a quiet "be good" or I'll be home before you know it." For special treats I hide cookies around the house while they are out in the yard right before I leave for them to have fun finding in those first few minutes when they may be concerned about our having just walked out the door.
Since you seem to have had lots of dog experience (your own and fosters) I think you can do a fine job with a spoo being happy in your home.
Lily AKC: CGC CD HIT CDX RN RA RE RAE RAE2 RAE3 NAJ NA; APDT: RL-1; CPE: CL1-R, CL1-H, CL1-F, CL1-S, CL1
Peeves AKC: CGC BN RN