When dealing with 'troublesome' internet connections, or just in general:

Keep page load to less than 50k, or 100k if you're feeling fancy.

Have a responsive design, unlike this website does, as a lot of people use phones, don't have a PC or are not on a PC.

Don't link everything under the cloud because you can - fonts, frameworks, huge pictures, because it makes your life easier. Self host everything, make it small.

And don't use JavaScript to add an unnecessary layer to 'manage' linking. Clicking on a link is expected behaviour. As are scroll bars. HTML links work perfectly fine and it degrades, nay I say disgraces, user experience.

These basic rubrics will ensure when serving things to 'troublesome' connections, be that bandwidth, blocked 3rd party CDNs or latency, and will largely make sure life will be easier.