I think it makes perfect sense to more than one cello if one has more than one residence. Transporting these large instruments is a nuisance.
I own two cellos. About a year ago I bought a second instrument - a much better instrument than my first. My first impulse was to give the first cello away to a young, needy student. But I've decided to keep it and use it on occasions when I don't want to risk my better instrument (such as when I have to leave it in the trunk of my car for a period of time). If it's stolen, I'll not be heartbroken.
Both instruments are similar enough in set up that there's no problem going from one to the other.