Just got a response back from miller tech. They said 30a is maximum and 10/3 is minimum recommended for 100'.
Im still with you guys on the 8/3 though except for price...

up here in the great white north,
$110 for 100' of 10/3 SOOW
$350 for 100' of 8/3 SO

cannot find 8/3 SJOW locally for the life of me