Why would it cost millions? The private US hospital might charge millions, but if you have a government healthcare system, the cost is basically paychecks + rent + equipment amortization + medicine + "other" (food, cleaning,...).
I'm not sure what exatly they did to the frozen woman, but for your MIL, that would probably take a few dedicated doctors hours, a few dedicated hours of nurse care (both spread out over the whole stay), some xrays and other scans, and all together would get up to a few thousands of euros max.... usually even less.
I guess the numbers are difficult to get exactly right but the cost per day at ICU seems to be about 50 000 2019-NOK in Norway [1] (70 000 the first day, half the next).
By comparison (in 2005 dollars), "Using data from 253 U.S. hospitals, Dasta and colleagues found that the average daily cost for ICU patients decreased from $7,728 to $3,872 to $3,436 on Days 1 to 3" [2].
$7 700 in 2005 is about $11 000 today, and 70 000 NOK is about $9 100 using exchange rate from 2019 and adjusted for inflation
None of these costs are real. They are artificially induced by the severe supply restrictions from the AMA limiting medical school seats.
Think of this instead as the value of 100 professionals in another field for a month. High, but much less than another person can produce in an entire life time.
I'm not sure what exatly they did to the frozen woman, but for your MIL, that would probably take a few dedicated doctors hours, a few dedicated hours of nurse care (both spread out over the whole stay), some xrays and other scans, and all together would get up to a few thousands of euros max.... usually even less.