Concealing a full-size 1911 is certainly do-able. The nice thing about 1911s is that they're pretty thin for their size, which makes carrying them a bit easier than some other full-size guns. Lots of people carry 1911s without a problem. The only way to find out is to try it for yourself.

I would recommend getting a good quality holster (i.e., Milt Sparks Summer Special II or VMII) on a good quality gun belt (I like Beltman's 1.5" double-layer gun belts).

FWIW, while I haven't carried a 1911 concealed, I have carried a 3" 65 in an IWB holster for 12-16 hours a day, under an untucked, button-down shirt. The weight is close to a full-size 1911, but is noticeably bulkier. I used either a Milt Sparks SSII or a VMII-style holster by another maker on a Beltman 1.5" double-layer gun belt.