my extended family is planning a trip to Sweden for a reunion around Oskarshamn in June of 2019 to have a reunion with our Swedish family members celebrate the 100th anniversary of my grandpa's immigrating to America. Since June is high season, how soon is too soon to book reservations for lodging? Any suggestions?
How many people are traveling? Do they need to stay in a single hotel, or could be spread out, even in close by towns (if needed)? How much flexibility does the group have? How big is the town you're thinking of, and what does the lodging landscape look like there (lots of hotels, mix of big/small hotels, proximity to other towns, etc)? I thinking starting with that kind of "background" info would be helpful. No matter what the answer is, you still have plenty of time - most hotels won't accept reservations more than a year in advance (as far as I know anyway) because they won't even have their room prices set this early.
It depends.....in some cities there is a specific hotel I want and will check their website or email them asking how early they open their reservation book. If you aren't sure which hotel, you can start with booking.com which extends through April 2019 right now. When you find a hotel you like, email them. I know people who go to the same place every year and make their reservation while they are there for the following year.
Also, if the hotel you want is booked, keep checking back. I booked for Croatia for summer 2018 last September. The place in Dubrovnik I wanted was booked already so I booked a different place. This past weekend I checked and to my delight, the hotel I wanted was free. I quickly booked them and canceled my other booking. I never book this far out without the possibility to cancel. If I don't go directly to the hotel, I use booking.com exclusively.