Quote Originally Posted by ThePolarBear View Post
Contesting 54

Yes, it is possible, assuming a character can know when spell slots will be refreshed at all to begin with.

"1 hour of" - list. If "1 hour" didn't apply to anything that is separated by the comma (ending in ", or") a different timeframe would be needed, like a new verb would be needed to change what action is applied to that particular element of the list: "Walking on brick roads, catwalks, or carpets causes ..." is different from "Walking on roads, climbing on catwalks, or caressing a carpet all carry the same risk of ...".

There is no other dependency to rest on: for example: "a period of strenous activity - at least ??? fighting" just doesn't work.
"A period of strenous activity - fighting" while correct and working as a phrase, changes the meaning that the presence of "1 hour of" clearly defines: that that part of the text is there to make explicit how long the "period" is. Thus such a meaning is not reasonable conclusion for intended reading: it's not just a list of activities.
Even if we were to take it as correct there's no defined period: it would still be incorrect to say "No" as a RAW answer. It would simply be "undefined".
R54

You are parsing the rules in a way that most people wouldn't. Discussing this would go beyond the scope of this thread, but OP or you can create a new one if you would like to further discuss this.

Casting spells during a rest interrupts it. This is why Sorcerers often use Extend metamagic with left over slots to do the same thing. An extended Mage Armor would last for 16 hours, after 8 hours of rest this results in the same effect as OP was asking about while abiding by the rules.