To have a controller "1.5 maybe 2 feet to the batteries" AND to ensure that on-board temp-comp doesn't work against you, you have to keep both controller and the batts in the same space, more-less.
Which means, you either have to put the controller on the trailer tongue out in the open - not recommended, or to put controller and batts in a big tongue box - OK for AGM but not so for flooded, or to put controller and batts into reasonably big storage nook - again, OK for AGM but with flooded there is an issue of venting, plus acid fumes affecting the controller.
