So basically using multi-Sig cold wallet on airgapped machine provides the ultimate security?
I was thinking what if someone generate the same private key as my address in case of single address (which is very very unlikely) but using multi-sig makes this impossible,yes?
The chance of you messing up the multisig, and losing access to your funds, is much larger than the chance of someone finding your cold wallet's private key. The latter is just not going to happen (unless you make a mistake), the former can easily happen.