Personally speaking @
wizzo227 I don't plan to do anything as I've always been in control of my usage and bills and so I'm fortunate in as much as the current prices are more of an annoyance than anything else.
Regarding the chap in his big house, there's a lot of unanswered questions such as how well insulated is the property, how old are the doors/windows, boiler etc. Presumably if he's confining himself to a few rooms and the bills are becoming a problem, then he doesn't have the funds to spend on the property.
The problem with getting a lodger is that they'd expect a reasonable level of heating, it's more rooms to heat with more doors opening and closing etc. Does the income from the lodger then get stripped back with the associated costs?
Downsizing is a logical approach but it depends on the condition of his current property, the location of where he is now and where he moves to etc. It's possible someone could downsize to a nice place and have significant cash in the bank after the fees have been paid. It's also possible that he could even struggle to break even or even make a loss, such as moving from a lesser area to a better one.
Whatever you do there's usually a financial cost to it, whether it's improving, upgrading, moving etc. The key to it is being able to analyse the options to suit your own situation, then manage it. It's surprising what can be saved from a usage point of view, replacing old appliances such as fridge/freezers can make a noticeable difference but it still requires expenditure.
I see no sense in downsizing to save money if a person has a habit of leaving all the lights on, the TV's on but you're not watching it etc.