If avoiding external noise or a dud room is a big issue for you, have you tried something like a DPA 4088 with a cello mount?
I know a session cellist doing a lot of work in everything from core classical repertoire to touring with rock bands playing in some major venues and she carries a 4088 with her for those days when she wants something that she knows will work in a difficult space and help the sound crew get the sound she wants with the minimum fuss. That said, in the studio, she usually uses a U89, Beyer MC740 or 4038 - depending on what sound she needs.
One fairly famous cello soloist I used to record often, initially insisted on a C414B-ULS or, at a push, one of the original TLM170s, but after many years we moved him off the 414 to an MC740 by showing him that it produced the sound he wanted without needing a shedload of EQ. (The first choice for one particular recording was actually a Brauner VM1 but the TV crew vetoed it on the grounds that it's rather large and something of a visual statement that the director didn't like dominating his shots, let alone the difficulty of hiding the power supply on stage so we switched back to the MC740.) Just before he retired we started using the V4U, which he picked in a blind AB test against the MC740, and that became his preferred mic for our last few recordings with him.
And to respond to your earlier question, if the 4038 gives you most of what you want but you're worried about a lack of LF, try borrowing or hiring one to try it out for yourself. As you're no doubt aware, the quite complex frequency radiation pattern for a cello means that moving a mic by a few inches can radically change what it's 'hearing', especially in the HF-LF balance so I think it might be worth trying to work that a bit with whatever mic you try. I've certainly never found a 4038 lacking in LF extension for a cello pickup; it can lack some extreme HF response but the lack of spurious resonances from the ribbon produces a lovely clarity without the tendancy to go 'fizzy' which can aflict even top quality capacitor mics.
To cloud the water a bit more, some other mics with which I've had good results on cellos, which might be worth trying but are less common and might be hard to find so I didn't bother mentioning them before but here goes: Pearl rectangular capsule models like the ELM A (switchable), ELM B (fig-8), ELM C (cardioid), CC22 (cardioid) or TL44 (switchable) or the Milab DC196 (switchable) or DC96 (cardioid). Then there's the more unusual Ehrlund EHR-M that I think Hugh reviewed in SOS at some point, and which has a triangular diaphragm. I've only used it a couple of times when wortking in Sweden but it was a really interesting mic with some very likeable sonic qualities on low strings. I also rather like the AEA A440 and A840 on cello but they're both huge and, particularly the A440, quite expensive and heavy. They also need really good shock mounting to avoid picking up stand borne vibrations - so really don't respond well to sitting on an un-shock-mounted stand sited within a few feet of a cello spike on a resonant floor!