What I do these days is use an iPad Pro and use a cloud-based virtual desktop [1] so I have the best of both worlds with me. The caveat is that you can't do this without internet access.
This is a neat idea, but I feel like an iPad Pro is overkill for accessing a virtual desktop. You could set up something similar with an old laptop for a fraction of the price.
Or an old regular iPad, if you like the form factor.