What are some popular TF2 maps that suit a low number of players?

I run a TF2 server, and I've noticed a problem in that there is maybe only one map I have in rotation that is suitable when only a few people are on the server. It's a dodgeball map, and I'd rather not have that be the gameplay that is the default for an idle server. Aside from that and one zombie map, the rotation pulls from the stock Valve maps. Are there any generally well received maps out there that aren't of a weird gametype that are well suited for fewer people? If I've overlooked a stock map, that would be ideal, but I'm wide open to suggestions.

Edit: I'm referring to maybe 6 or fewer total players here.

Solution 1:

If you don't mind playing as a sniper, Sniper Paintball RC1 scales down well.

However, why not just enable bots?

Solution 2:

Arena and King of the Hill game types are well hosted on maps which are not that big and have overall acceptance.

I would suggest Watchtower, Sawmill, and Lumberyard.