How big should be a regional map?

Hello guys, I'm using ProFantasy softwares to make maps for my campaign. I'd like to know how big are your province/kingdom/continental maps. For example, D&D 5e DM Guide states that a province scale map could be represented by a hex grid, with each hexagon equal to 1 mile. Kingdom maps (for countries like UK) could be 1 Hex = 6 Miles. Continental maps could have each hexagon equal to 60 miles. How do you deal wich such things? The focus is on distance between places, to calculate how many hours do the players have to travel to go from A to B. Could you give me some examples of maps along with page and grid dimension? 

Especially when using hexagonal grids, you'll probably want to stay within 100 x 100 grid dimensions. Splitting up maps between pages is recommended, especially if you or any players are using older computers. This is touched on in the Graphics Rendering Performance section of the Wiki.

I personally am using 10 x 10 pages in Roll20 for my regional maps, with a scale of six miles per hex. This is mostly because each hex is a graphic on the map layer and it cuts down on lag. It also helps make discrete and distinct areas, much like an MMO... which may not be realistic, but helps create a flow from one area to the next in a hexcrawl.

I don't really map smaller than that... such as the one mile hex. That just gets tedious with large amounts of blank area or lots of time spent adding filler that may or may not ever get used. A lot of that filler can be handled via a simple location note in a Roll20 handout for that hex location.

Thanks, I like the idea of making a regional hex map with discrete symbols on each hex. I was thinking about a more "artistic" looking representation, but probably the one you suggested is better for the puropses of the game. Is there any simple way to know how to calculate hex dimensions in pixels? I've made a little research but it seems more complicated than squares. Although I could simply divide a bigger map in many 10 x 10 hex sheets, I'd like to get some tips on how to draw a map of a whole kingdom. Payers won't use that for travel, but It would be nice to draw it with a reasonable scale, just to let things stick into a reasonable threshold of realism. I feel so dumb about these things XD

I provide some more info. A larger map doesn't need to show too many details. It's just to represent political borders and some major geographical features. Assuming I'm talking about a Kingdom, like Italy, that could  be wide 372 miles and long 801,86 miles  (wikipedia states that Italy is 600 km W and 1291 km L, so I divided that numbers for 1,61 that is the km / mi ratio). As I said I won't use this scale to measure players travel distance, but just to give 'em an idea of being in a bigger world than the simple locations where adventures are set. If I use a standard V hex grid (75 x 88 px) and made each hex a 60 miles space, I would need just a 7 x 13,35 page. So I could use an higher resolution and more hex. 20 Miles for each hex for example. Now, I've noticed that the crucial factor for a tidy looking image on a screen are DPI. The more DPI it has the better it looks in general and when you zoom in. The rule of thumb is to keep the amage below 5 mb. I know my message could be a little blundering. I repeat, it's just for my knowledge and I'd like to know if I'm on the good way or I have to go back to school because I haven't understood nothing till now XD. Thanks. 

140DPI .jpgs should look good at 200% zoom and have a minimal file size. The Image Best Practices for Roll20 Wiki page discusses this, too.