I'm putting together a list of places one can go that are conducive to retreat of one-month plus, preferably in the Insight / Vipassana / Theravada tradition. I live in the USA, so the list is skewed that way, but open to anywhere in the world! Please let me know if you are familiar with any retreat centers that would be good to add to the list!!  Below is what I've got so far:

A typical group retreat, with a set start and end point, a community, a teacher, etc.: 

• Southern Dharma has a month-long retreat in winter (affordable'ish)
• Spirit Rock has a 1 and 2-month retreat in Winter (expensive but with scholarship options)
• IMS has a 6-week and 3-month retreat in autumn (expensive but with scholarship options)
• Boundless Refuge led a 3-month retreat the last few years, combining Zen and Vipassana

Places where it’s a little more self-guided but with teacher support:

• SBS in Malaysia, see “guided retreat” (dana-based)
• Kevala Park in Wisconsin (dana-based)
• The Forest Refuge in MA and Vipassana Metta in Hawaii(both expensive)
• Dharma Treasure in Arizona (affordable'ish) ​​​​​​​

Theravada monasteries w/ work practice & not in noble silence:

• Wat Metta w/ Ajahn Geoff in San Diego
• Various Ajahn Chah-branch monasteries in the US and abroad

Theravada monasteries in Asia w/ no work practice. Note I'm leaving out Myanamar-based monasteries due to their current civil conflict.  

• Panditaramas in Lumbini and another dozen places around the globe. Also good for long-term Mahasi practice is Nissarana Vanaya in Sri Lanka
• Wat Phu Khong Tong w/ Ajahn Martin in Thailand (Ajahn Maha Boowa / Ajahn Mun lineage)
• Pa Auk branch monasteries all over the world; Na Uyana in Sri Lanka comes particularly highly recommended

I'd also be interested to hear if people know of affordable places where one can stay with no guidance, like renting a cabin in the woods w/ a kitchen, or where one could stay at a Monastery in Asia long-term, even if no teacher support.

I think your list is fantastic congratz!

Here's a funny, very funny and actual recommendation:
Go to a mental hospital with an Esquizophrenia diagnosis or a similar one.

They give you food, medication and you only need to sleep and meditate.

I did so much magick in two months inside a mental hospital you wouldn't believe it. Could link you to examples