I have to agree that double yoke eggs can be a sign of reproduction problems since a hen I had laid huge single and double yoke eggs in the beginning of laying. When she was a year or so old she would only lay lash eggs here and there and seemed to developed crop problems also which killed her.
My girls surprised me with eggs this past week, just 1 or 2 a day but it has been 2 months eggless do to short days and molting. Now that adds a extra trip to the coop a day to get eggs before they freeze. :D
36 yesterday, from the store. ☹️ Haven't got an egg for 2 months due to short days and all the girls molting. My wife is starting to ? why we have them.:hmm
I have always just gave them water a couple times a day when freezing out. This year I bought a electric dog bowl ($18) and it has worked great, we have been 8 to 10F below the last few days and it hasn't froze.