Consider how valuable your data and your time is (to you). On such a basis you might well consider it worthwhile spending a small amount on another internal HDD to plug in in place of your existing one (i.e. so that your existing internal HDD is disconnected) so that you can try a restore without any risk.
Not only can you prove to yourself that it works (at least I hope it does), but you will have familiarised yourself with the restore procedure so that if it ever comes to it you can restore very quickly and somoothly.
Basically this is putting in place a Disaster Recovery plan AND testing it.