The coldest we have had is -10C (14F)
3S 4P would work
3x40.4v is 121.2v
4x10.6A is 42.4A
Would have to use 15A fuse in the combiner box for each parallel string
Want a 48v system with about 5kw in panels.
Would have to use 150V / 70A controller because it can take 4000w @ 48V