This organism in particular is so small it can likely make use of more hospitable microhabitats than some of the flora (and indirectly fauna) it's bringing over. But if you mean "this species" as in its role in spreading other species, yes, a Fermi Xeric Scrubland or semidesert woodland or "Spirepipe Forest" of some sort would make the transfer more plausible. (Yes, "Spirepipe Forest" sounds like a good name.)
Ringtailed Ketters, given their shape, small size, lack of integument and wings, would probably have trouble living in the tundra during its cold months, and there's no mention they're seasonal or live only on the fringes of the habitat. Ringtailed Ketters living in Fermi Desert might be more plausible. If a scrubland of some sort provided the occasional hollow log or burrow underneath a tree, it could plausibly allow a small population of Ringtailed Ketters to survive in its warmer latitudes until it yields a better-adapted descendant. (see northern bats, which are much smaller at 6.4. cm, but do have an integument and hibernate in colonies.)