Tipps for visiting Iceland this Winter?

Hey, this Winter I will finally visit Iceland with my girlfriend for Christmas.

We will rent a car so we can do the golden circle tour, visit the blue lagoon, or sky lagoon. (We are not sure which one yet)

I have some questions and would really appreciate your advice:

1. Hot Springs and rivers in winter Is it possible to visit natural hot springs or rivers like the “Hot River” near Hveragerði in winter? Are they open and safe to access? Can you actually swim there during the colder months?

2. Rental car Secondly about the rental car, should we take a all wheel drive or is front/back wheel drive enough to get around in the winter?

3. Blue Lagoon or Sky Lagoon Would you recommend the blue lagoon or the sky lagoon, or maybe somewhere completely different? Both are not possible, because of a Lack of money 😂 we both are university students so money is a bit tight, which brings me to my last question:

4. Food Prices We’ll be staying in Iceland for 5 days, and our hotel includes breakfast. But we’ll still need dinner every day. We would definitely want to try some real traditional icelandic food, but also cheap standard food like pizza or pasta. What should we expect in terms of prices for that? And can you recommend some places we should try?

5. Other Tips?

• Do you guys have any other tipps for our visit?
• Maybe what we should definitly see/do?
• Something we should include in our golden circle tour, something we should not miss on the tour? - Some must-see/do in reykjavik (our hotel is directly in reykjavik). Or maybe Tips for things we should bring with us for winter in Iceland?

Thank you all so much in advance ☺️