Using a Printer / Scanner with NO Internet Connection (HP 7640 or Scansnap ix500)

Apologies if I'm in the wrong forum, I did not see one for printer questions.

I would like to scan documents to, and print documents from my mid-2014 Macbook Pro 15" Retina, running the latest OS X Yosemite 10.10.5, WITHOUT needing an internet connection (or wifi.)

Can I hook a newer HP (like the HP Envy 7640 e all-in-one,) directly up to my macbook via an Ethernet, USB port or some other port/chord/line, and do all printing and scanning back and forth that way? I'm headed to a spot with no internet (and no wifi) and am having trouble finding an answer before buying this printer! I didn't realize Apple had some compatibility and use issues with some models of printers/scanners until just now.

I'd also like to buy a Scansnap ix500 and do the same thing (no internet connection.)

I will have internet connection DURING THE SET UP ONLY, so I can download the latest drivers, versions of software and make sure everything is working before leaving for a non-wifi/internet zone.

I could also buy a little hootoo portable router (or any router!) if anyone can confirm that this would assist in hooking the devices together for scan/print operations by setting up a local wifi network. I've never done that before (without internet) but I'm happy to buy whatever if it will work. We have plenty of electricity. Would setting up a localized network with no internet connection be the way to go?! We could also buy an Apple Airport Time Capsule which might solve several issues and provide a local backup -- what do you think is the best set up?

Summary of questions:

1) Can I hook up the HP 7640 printer/scanner with a wired connection to my macbook pro (using ANY port or adapter.)

2) Can I or should I set up a local wi-fi network using an Apple Airport Time Capsule, to facilitate any

3) Internet will only be available during a brief set up period (so devices/software can be updated.) All devices will be moved afterwards to an internet free area and need to be able to scan and print to/with the macbook pro.

4) Specific item purchase suggestions are welcome. (Scansnap ix500 and HP 7640 printers/scanners are being considered. Airport Time Capsule?)

Thank you for any assistance or suggestions you can provide!