Years ago I had real problems using a 172 IFR in the northeast. If
there was a big messy front, the airplane didn't have the legs to get
to destination then to an alternate with enough fuel. It was OK for
training and very soft IFR. A 15X would be even more problematical.

Even with the M20J (Mooney 201) I replaced it with a reasonable
fraction of planned trips (maybe 10%) were cancelled because of
weather. Icing, embedded thunderstorms, stuff like that had a way of
keeping the airplane on the ground. Lack of range didn't often play a
role, though.

It depends on what you want it for. In my case, I had clients I wanted
to see on a reliable basis, so being able to say "be there at 10
tomorrow" had to be realistic.