Yes sadly most will be too frail for the treatment techniques used in ICU.
Some interesting data in this for anyone who is interested in this sort of thing. Over 85’s are clearly the biggest admission group to hospitals but 65-74 for intensive care. I presume that’s because they won’t allocate intensive care beds to over 85’s when demand is so high?
This will be an issue with the icu capacity problem, this probably won’t go down until vaccinations have moved down into the lower age group.