You can use a dedicated offline raspberry pi running electrum or something like that.
That you only use to sign transactions.
And have a watch only wallet on your daily computer, used to prepare and broadcast transaction.
And your long time holdings should be on paper wallets.
I don't think this would protect you from the government. The government has the ability to to search your property (as well as to seize your property) so they could easily take your raspberry pi and get the private keys