To warm up or not to warm up, and...?

IMO from what I have read it is not so much the heat that will degrade the unit as much as the heating cooling cycle. This is why most high end manufacturers recommend you keep your equipment on all the time. They use components that are designed to handle high temperatures. Where those components start to fail is when they are put through constant heating cooling cycles (on off on off). This will cause expansion and contraction that will lead to failure. Example I run my old Sansui 70/70 in my wife’s business it has not been turned off for 28 years except for blowing out dust and is still running strong. I do not see an issue with your situation as you are still maintaining constant temperatures. As for the sound trust your ears and don’t over think.

i hear better sound quality when my amplification gear - tube or ss - warms up, usually from 10 to 30 min in

we are talking about hegel, van alstine, odyssey, ayre ss gear, as well as cj, arc, pl, air tight tube gear

that been said, i am careful to keep hot running tube amps cool and air circulating... use quiet fans to move the air past the power tubes e.g. 8x kt88 kt120 etc etc... i am pretty convinced  (as is ARC) that letting these high power tubes run cooler makes them last longer

For those who don't understand, the winking smiley face means it's a joke, not serious. 

1) Leave your equipment ON 24/7. At least try it! Cost me <$1/mo.
Do you really think that amp is going to “burn out” before you do?!!
2) Use fans or coolers ONLY if the piece is very hot to touch. (solid state NOT tubes.)
3) Aim any cooling airstream AWAY from the gear not AT it. Don’t blow the hot air back onto the tubes/circuits.
4) Use extra caution with cabinets/enclosures and component stacking.

Let's try this again: 

Live in Alaska and keep the windows open!  ;)