Time to leave Liquid Web - could use some advice

I run a small web development agency and have been hosting 150–200 sites with Liquid Web for over 10 years. I used to love them, but they’ve gone downhill over the past year. I tried to stick it out, but we just had a major outage in the middle of a training session with a larger client. Between constant outages and a general lack of communication, I’ve had enough. Sorry, Liquid Web. I used to love you, but now you’re officially on my shit list.

I’m now looking for a US-based managed hosting provider, and I’m sure I’ll find one, but the thought of migrating everything scares the hell out of me. It’s not as simple as cloning sites—many of our clients manage their own DNS, which means updating IP addresses is going to be a challenge. This is going to be a massive project for a small agency like ours.

Has anyone here handled a migration of this scale? What should I watch out for? And more importantly, who did you switch to? Managed hosting is a must as I'm not a server tech and don't have the time to learn how to be one. We're on a Linux cloud VPS with WHM. I’d love to hear your advice, tips, or recommendations on where to go next. Thanks!

EDIT: For the handful of you who have messaged me directly (and for those of you who want to)... I ignore and block unsolicited messages as a general rule. Just post what you have to say as a reply. I'll let you know if we need to make it a private conversation. Thank you for respecting my boundaries.

EDIT 2: Well...This post got some attention, so much so that somebody at LW saw this and a senior supervisor from there called me this morning to discuss it. I guess we'll see what comes of this, but for right now I'm hopeful.