I have question to any DM who runs sessions: How many battles PER session you have? Sessions last, what 2...3 hr?(unfortunately i never had a pleasure to play at the table D&D). with the limited rest to my knowledge how the spellcaster would work?
Depends

Certain games are meat grinders, some are narrative and politics driven. I hate large initiative counts because of map clutter and sheer amount of time it takes to go through the paces. So, I usually make smaller fight sizes with creatures who have multiple abilities to deny a boxing in by a druid summoning 8 wolves, all with advantage, each bite requiring a str saving throw or be knocked prone, their attacks are magical at druid level 6, and the creature cant move because all squares around them are occupied and just get melted. My fights usually take about 2 hours and we have a solid 4 hour session, Saturday games have gone as long as 10 depending on the players' thirst.
My personal style leans towards encounters of environment, social, political, and combat. So they have a lot of "encounters" a day, they just arent all fighting. If I averaged it out, it would probably be 1 encounter a session but translate to 2 encounters in game days.