Meaning: come whatever the worst you can imagine
Rewrite 1: come flood or ice storm
Rewrite 2: come my mother-in-law or the IRS
Rewrite 3: come tax time or bankruptcy
Rewrite 4: even with the threat of prison or cleaning the toilet
Comment: I had a wonderful relationship with my mother-in-law, so that example might not be all that terrible for some people. In general, come up with a list of the worst things you can imagine and try to play them off each other; for instance, bad visits would be from your mother-in-law and the IRS; bad weather could be floods and ice storms, and so on.
Note on capitalization of "hell": I thought it was standard to capitalize "hell," but in looking at various online dictionaries, and even the Associated Press Stylebook, it is standard to use lower-case "h" with capitalization secondary. However, the Associated Press Stylebook and many (not all) online dictionaries say to capitalize Hades.