I don’t know C_G so this comment is not to be taken personally.. and while I like merino thermal’s personally may I just offer one word in support of onsie’s.
Could offer you the loan of quilted overalls in 42 long, as worn offshore North Sea, winter. Sew up the ends of the legs, job done. Only lacking a hood. Warm, hardwearing, lots of zippy pockets, natural cotton.
I’d leave Mrs STR if she bought/wore one of those abominations.
If I ever had a mental breakdown severe enough to wear one myself, I’d commit suicide.
Fortunately, I still have my credentials and Mrs STR is running quite warm at the moment, so has taken to wandering round the house in her skimpies and an old checked shirt of mine, fastened with two, one, or no buttons 😈