I had one of these this past season. A massive filly that came out big enough to ride! The 3 vets and 2 farriers that saw her have never seen such a big foal.
She was on tip toe in front and had one hind quite badly contracted with the fetlock knuckling forward. Although healthy and very strong, she found it very difficult to stand still enough to suckle and she was so tall that she had to bend down to reach the udder. She was bottle fed initially until she could work it all out for herself. She definitely shivered and trembled everytime she stood and her knees would often look like they were going to give out. I don’t recall her sweating but I did notice the effort it took to drink and the resulting flared nostrils/big breaths/heaving ribs.
Over the next few days she was given antibiotics and 2 shots of tetracycline. She had the heels of all feet scraped with a file every 10 days or so to help lower the fetlock. It took a month or more for her front legs to relax sufficiently and for her knees to straighten. Her hind limb took longer. At 2 months old she had an acrylic side clip added to her hind hoof to correct a minor deviation in the pastern/fetlock alignment.
On the advice of 2 vets (plus the farrier) I weaned the filly at 3 months in order to better manage her feed intake and growth. This was not something I did lightly but her mother had a udder like a cow and the filly was gaining weight at an alarming rate. I was advised to take some of the weight off her ribs and to keep her fairly light while her limbs were straightening. She lived in a small flat grassed area next to the mare - big enough for a bit of a trot but not enough for a full scale hoon. I noticed she would sometimes sneak drinks from the mare through the post and rail!
She is 5 months old now and her legs are the same length and size as my adult TB! Heaven knows how big she will finish. She is still marginally upright in the front pasterns but this may be attributed to the stallion as it is a trait he sometimes throws. It is not enough to be considered a conformation fault. The hind limb deviation is totally corrected and both rear pastern angles match perfectly.
I have noted that she is VERY prone to breaking the toes of her front hooves away, leaving them steep and dumpy in front. It suggests that she is still weight bearing a little too much over the toe and is something my farrier is working on.
I have some photos somewhere which I could send you. I hope this helps - I know how beneficial it is to hear similar stories!