$signature = @'
[DllImport("kernel32.dll")]
public static extern void GetCurrentThreadStackLimits(out uint lowLimit, out uint highLimit);
'@

$type = Add-Type -MemberDefinition $signature -Name Win32Pinvoke -PassThru

$low, $high = 0, 0
$type::GetCurrentThreadStackLimits([ref]$low, [ref]$high)
($high - $low)/1MB

Name                           Value
----                           -----
PSVersion                      7.2.3
PSEdition                      Core
GitCommitId                    7.2.3
OS                             Microsoft Windows 10.0.22000
Platform                       Win32NT
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0…}
PSRemotingProtocolVersion      2.3
SerializationVersion           1.1.0.1
WSManStackVersion              3.0