This may or may not be helpful, but I just had a visit for a scheduled surgery in early December, my first time at a surgical clinic of this type. My mare was scheduled for sequestrum removal surgery (bone chip).
I thought I’d hand off the horse and that would be it, but it was a long and detailed process. A tech met us at the trailer to assist with leading inside if I needed help, but I led my mare in myself. A second person also came to the trailer to collect her things. I had pre-bagged feed; I did not bring anything else to leave there with her except for her halter and lead, onto which I added name tags with her/my name, and the paper intake sheet that had been requested with very detailed areas for feed, supplements, etc.
We went into the surgical facility (quite an experience for my young mare and I!) and spoke briefly to the vets before we went back outside to do a basic lameness exam. A tech took her for the trot up, which was wonderful because I could watch (typically I am the one trotting along). They then took her to do x-rays for about a half hour. I was not allowed in the x-ray room due to ray exposure but could stand right outside the concrete walls. After this, we all went over to the examination bays (open wash stall type units) and the vets did numerous ultrasounds that I was able to watch. She was not sedated for x-rays but was sedated for ultrasound (horse dependent). There were cross ties in the examination bay but a tech held her lead rope.
We discussed the results and it turned out my mare possibly did NOT need surgery due to some very positive changes since her last ultrasound. We did some treatments while there and the vet wrapped her leg at the end with a standing bandage from padding, elastikon, that fibrous brown wrap, and vetwrap. I cannot speak to the surgery portion myself, since we ended up not doing the surgery thus far. However if she had needed surgery at that point she would have been taken to a stall that was already labeled with her name and prepared for her and kept until the next day. I would be allowed to watch the surgery if I wanted. I had spoken to vet previously and the bandaging after surgery sounded very involved - you could have a set of standing wraps in trailer, but I believe they will do their own complex bandages after surgery (I was advised I would likely want to have a veterinarian come out to do bandage changes for at least a few weeks).
I received discharge instructions verbally from the vet and written instructions the next day. I went to pay my bill while my horse was put in a stall. I was able to talk about all my questions and concerns with the vets while a tech was holding my mare so I could focus on them and not splitting my attention between the two. At checkout, I was asked if I needed help loading, which I declined (my mare is typically good, and I had a helper/emotional support person with me).
The facility was very quiet and calm. We saw a few other horses in stalls, but no horses were actively being led/examined at the same time for this first visit. At subsequent visits, a horse was led past us briefly, and at another, a horse was in the surgical suite receiving surgery (being lifted with a hoist).
My mare has thin soles and was unshod at this time (typically wears glue-ons or boots when in work on varied terrain but does not require them for stall/paddock). She did not need shoes at any time during her visits. The stalls are, as mentioned above, padded and thickly bedded. The vets were mindful of her trot up on pavement and I told them she has thin soles. There is no turnout at the surgical facility I went to, so there was no concern for rocky footing. I personally would not bother to shoe.
Re: blankets, the barn at the surgical facility I went to was heated to 55 degrees (this was indicated in literature). My mare uses a blanket typically only when it is in the teens, so I did not bring one for her. You could ask about the temperature control in the recovery barn and determine what might be needed based on that. I did bring an assortment of coolers for the trailer because my mare can get nervous alone in the trailer and start sweating. I did need to use them for trailering and was glad I had multiple. I would bring a labeled/tagged stable blanket and determine at arrival if it was needed to leave it there.
I had no idea what to expect and was extremely nervous for our appointment. It was a positive experience (as much as needing this type of care can be) and the vets were extremely kind, knowledgeable, and thorough, and the techs were all wonderful with my mare. It was all very calm, clean, and low stress and I had the opportunity to discuss with the vet without needing to keep an ear and eye on my mare, which was one of my concerns (farm visits by my regular vet often include this complication, where I’m managing two things at once).
Hoping you have a positive experience and great outcome!