It’s going to depend on which charger you install (they have different power requirements) and the local electrician rates. For a Tesla home charger, generally figure around $2000 for equipment and labor, assuming your breaker box has enough capacity and doesn’t need to be upgraded.
I think it’s more nuanced than that. IF you get one of the longer-range (250+) Teslas and IF your trips are along routes with decent access to superchargers, they can absolutely be used for long trips.
In general at this point if you’re going from any big city to any other big city, you’re fine. Miami to LA? No problem.
If, however, you’re planning a trip off-interstate in flyover country (for instance, Minneapolis to Mt. Rushmore) then en-route charging will be much more of an issue and you will probably have to detour away from the quickest route in order to have charging available. You can still get there, but the trip will be a bit longer.
Also, current (see what I did there?) electric cars often have 200+ miles worth of range even if you don’t get a Tesla, so it’s no longer such a requirement for your office to have a charging station for commutes. Even the comparatively short-range Leaf now gets a minimum range of 150 miles (and there’s an option package to get that north of 200), and even dropping that by 1/3 or so for winter conditions will leave you with plenty of range to get to work and back, even with a trip to the store thrown in.