Yes - but I don't have rats - just field mice. Mice can get thru some plastic if they are determined enough - but they usually don't try on plastic containers - just thin plastic wrappers. Squirrels, raccoons, possum, etc. - those might try. Generally inside the house I keep things like rice/etc. inside plastic bottles/etc. - the dollar store often has one gallon plastic jars. Local guy has thick plastic 55 gallon drums with snap on lids that I am going to get to put smaller containers/etc. into and put those out in the shop.Rats will get through just about any kind of plastic container. Plastic inside metal is a good idea.
Time and energy. Good thing is that my house is well insulated. Having an alternative means of heating the house and cooking is good. My woodstove serves that purpose. I also have a somewhat insulated shop (the rollup doors are not insulated and neither is the roof or the concrete floor and the windows are single pane) - if I have to, it can serve a backup shelter. If someone else has to take shelter outside my house then the shop will keep them out of the rain and wind - especially if they have some kind of camping shelter like a trailer/RV/tent trailer.The luxury of time is one thing that will be difficult to deal with in its absence for many of us. All kinds of routine tasks made easy by modernity go south in bad times, suddenly consuming way more time than we are used to. One example: Staying warm.
My next residence will probably be earth bermed ICF with hydronic floor heating using a geothermal heat pump powered by solar - so much more off the grid.