My group is too big for my game, how to manage this situation?

So I may have a happy problem. I just finished a game with a group of five players, all of them enjoyed it and we’ve been talking about the next game we would start. None of them are problem players, none of them will refuse the invitation (I think) and ultimately all of them are friends and will know if one is excluded.

However, I find five players to be too much for me: due to the nature of the game we play, the kind of situations I like to set up and the time it takes to go through so many people while having some RP in there. Those issues make it so I have trouble running the game I’d like to run. Making it less enjoyable for me and, I think, for some of the players.

So… How can I, as a GM, deal with a group that’s too big for me if I don’t want to force someone out?

In a perfect world, one or two of the players would drop out of the game of their own volition. But realistically, I would like to drop one or two, which I don’t know how to go about making it happen, or make the game more manageable for the group I have.

Here are a few complications I have:

  • Everyone is friend of everyone else, so merely not inviting someone is just excluding them and hoping they don’t notice or don’t mind being left out.
  • Likewise, everyone seem to be looking forward to the next setting. So I don’t expect anyone to turn down the game unless there is a big change of playstyle.
  • There are no obvious problem-players. The worst I have are follow-along-players. So I have no real ground to expel anyone.
  • The playstyle I’ve found most enjoyable is one of low-combat and more RP and problem solving. Making kind of hard to engage five people.
  • I also find I like to take the time to RP a bit even when resolving mostly basic rolls, so that resolving a full day’s exploration in a single roll and narating the result is not something I want to do frequently.

I found some question close to mine on the site, the closest I have is this one: How can I manage a party that has grown too big?. But it doesn’t help my problem. Mostly because on the focus on Roll20 and dnd (we run a homebrew system for which the closest comparison I have is: Dungeon World with crunchier combat).

For reference, Here are the main avenues I had in mind in case I still have five players for a while.

  • Run the next game in a Westmarch-like style. Off-loading the burden of who is present to the players and giving me a reason to apply time pressure on the players. I’m not sure how feasable this is and may have to resort to selecting two nights instead of one. Based on our current speed. I can’t see how we could run a satisfying game in such a short time (that is partly my fault).
  • Keep the group and keep a close eye on the playtime IRL, keep things focussed. This is what I’ve been doing and I know it has the side-effect of giving little to no spotlight on the players who goes in the wrong direction and the difference between right and wrong direction is jarring in my narration (and I know some players noticed a few time). If someone decides to leave because of it… I can slow down because I have a more manageable group now. If noone dislike it, then I may be alright. But that is not the kind of game I’d like to run.
  • Keep the group and enforce a strict no-splitting rule. See how it goes. I tend to find 5 players+NPCs scenes tough to run and I expect the two least vocal players to just quit talking in such a game. But I can’t find another