Hosted a 7 hour house karaoke party ... here are my observations.
I find these kinds of posts useful when others do it so I thought I would contribute my own experience.
I hosted a karaoke party that started at 7pm and ended around 2:15am. There were lots of "pre-gaming" for testing with my immediate family before people started arriving.
For software I used KaraFun Pro v3 using the Integral catalog. That way I had access to more songs and since it was not in a commercial venue, I had no worries about licensing. I only had to resort to YouTube 2 or 3 times over 120 songs that we performed.
I also used my own software called StageKit Lightworks which controls the old school Rock Band Stage Kit lights, strobe and fogger. I had it modified so I was running three RGB light pods and a fog machine. Fog was kind useless between the A/C and the overhead fans not letting it spread enough. But the lights were cool I think.
The laptop was a 16" Lenovo Legion Pro i5 in high performance mode. It ran for over 20 hours (before during and after) without missing a beat or overheating. Very happy there.
The video came out of the laptop via HDMI to a Samsung 75" TV with a splitter so I had audio out via optical to a Polk sound bar with discrete bass unit. Again, house party so this was more than loud enough.
The singing was done through a JBL PartyBox 320 that was only used for the mics. I used two JBL PartyBox wireless mics. For a third mic I used a Behringer XM8500 XLR mic with a Cable Free Guitar UHF wireless system (this is life changing if you hate XLR cables). So three wireless mics. The PartyBox speaker sounds great but it definitely lacks the "auto tune" ability of a mixer. I think that's going to be my next investment. Something to put between the mics and the speaker to improve voice quality.
Everyone loved the set up. Since I was using KaraFun Pro I printed a couple of QR codes plus had the QR code on screen. I made a custom logo and had it displayed on screen. And had the scrolling banner. Worked out great.
The only gripe, and really, it's a minor gripe to be expected...all three microphones starting losing power around the 4.5 hour mark. The receivers from JBL and CFG never ran out of power. But the mics did. Luckily since I had three I was able to charge two while one was being used and they charge pretty fast. So it worked out.
I'm not a paid advertiser for anybody. But I do recommend KaraFun for no frills set up. It really just works. I love my JBL PartyBox 320 and I use it a lot for music listening and it's loud as hell with good battery life. But it's also essential as a separate PA for karaoke with the wireless mics. And my latest addition is the Cable Free Guitar UHF wireless system that lets you convert an XLR microphone into a wireless system. Really was surprising how well it worked.