No, solvers do no-where near 1.8 million nodes.

The solver I work on (minion), which is not optimised for arithmetic problems, or easy problems, does 86 search nodes when finding all 4 solutions. It makes no differences if the domains are 0..10, or 0..100000, in terms of either speed or search size. I would be amazed if any CP solver doesn't tighten the bounds straight away to something like:

    {0..7},{0..5},{0..4},{0..4},{0..3},{0..2}