There's only one 16" Dell model - the Inspiron 7610, aka the Inspiron16 Plus, and it's available only with Windows -- not Linux. If you're looking for a 15" system, that's a different story - there are indeed Inspiron/Vostro, XPS and Latitude models that do ship with Ubuntu.  
(No other category appeared to fit.)  I just bought an ACER laptop for my wife who is an Alzheimer's patient.  She spends most days playing Linux solitaire games (mahjongg, etc.) as she watches TV.  The problem is that it appears to be impossible to install a Linux distro on that machine. It came with Windows 11 Home S installed on it, and even after taking it out of S Mode, it appears to be impossible to access the drive to install any other OS on it.  It's locked down very well. My personal laptop is a Dell Precision M4800, on which I run Solus Linux, so it occurred to me that a Dell laptop (not necessarily a PRECISION workstation) might work for my wife.  But I don't want to buy one and find out that, like the ACER, it's not possible to install Linux.  Can someone please recommend a 16" Dell model that would be suitable?  It doesn't need to be very powerful (i3 would be fine), and it doesn't matter to me what version of Windows it comes with, just as long as I'm able to disable Secure Boot and install Solus on it.  Thanks for any help with this.
Laptop for Linux