It can be done, but it takes preparation... if just overnight/a few hours of below 32, easy enough, but if prolonged or HARD freeze - more prep...
Some rv's have '4 season' packages including more insulation and heating pads for holding tanks.. many do not though.
Some use something like this
, some turn off all outside water and drain the lines (including sewer), some just put put potable antifreeze in p-traps and sewer tanks (not fresh!)
You must protect the pipes from freezing - either by full winterizing, draining all lines and blowing out with air, or put heaters/lights in the basement..
You MUST turn on your furnace to keep temps above freezing - NOT electric heat/heat pumps as they won't warm basement...
good luck and if you are just asking this... I hope none of your pipes/connections/fixtures have frozen already. you'll find out the first thaw and it's part of the learning curve.