I own a Sig and I own a 1911, but most importantly, both are in .45acp.
I like the ergonomics of the P220, mine is a 1986 W. German model I bought new when it was new. My 1911 is a Kimber Custom CDP II.
Thoughts...
I'm a fan of large bullets, so the choice for me is simple - .45acp.
Try both a 1911 and a Sig, see which fits you and your needs better.
Ask yourself if a 9 or a 45 suits your needs, both pistols come in either caliber.
I shoot the 1911 much better - one ragged hole at 15 yards all day long while the Sig shoots more of a 3" pattern, still effective, but not laser beam like the 1911. Perhaps it's me, not the pistol.
I like condition 1, some can't handle it, so the Sig offers decocking.
You're the field general here, you make the call.