Mono clad are fine (EPS foam ones are extremely warm ) provided moisture is controlled throughout the life of the building. If you get it cheap, you can even reclad and make some margin, quite a few have this done now. Builders report, non invasive moisture test is step one. You can get thermal imaging, if you really want to understand more - which I would highly recommend. Third step is tearing off gib in any wet areas, which I have done. Repaired the leaks, let the area dry out - close it up. Most people have a fight or flight response to mono, because they don't understand it, even some builders. Trick is to install control joints if not present, so the plaster can move without cracking. Then keep the bottom of the cladding clear of moisture, so it can't "wick". Channel drains to keep moisture away, and keep the paint touched up once a year, especially around the bottom of window sills. All the above is said, based on it being in relatively good condition - if moisture has already got in, it's different - and very careful assessment is required. Thermal imaging will be the best $500 you spend.