There are lots of ways to fund it - some people just save up the cash before they leave, others pay off the house they live in asap, then rent it out and live off the rental income, others who haven’t paid off their house yet will just re-finance it and pull out some equity and use THAT to fund their travels. For us, since we intend to do this indefinitely, we are playing around with earning money online to supplement the funds we have currently.
Because we travel slowly, fitting in work and sightseeing is doable. Our schedule so far this year was 1 month in Maui (budget buster!!!), 2 months in Bali, 19 days in Siem Reap (Cambodia), 3 months in Penang (Malaysia), 1 week in Singapore (visa run since only allowed 3 mo. at a time in Malaysia on a tourist visa), now in our 2nd 3 mo. stay in Penang, then will go back to Bali for 2 months etc. On the other hand, if we were hopping around from place to place every week or two, we’d all be burnt out and exhausted. I was talking with another traveling family the other day and they’d actually had moments where they were like “Let’s just go home - I’m sick of this!” - but they are traveling much faster than we are, and staying in 1-room accommodations mostly (that’s for a family of 4) - as any parent knows, cramming the entire family into a 1-room place for months would not be ideal. Whereas if you travel slowly, your budget can allow for more spacious accommodations - case in point, we are staying in a gorgeous fully furnished 1450 sq ft modern high-rise condo with swimming pool, playground, gym, and laundry service right now for $33 per night. They are paying the same price for a single room in a guest house. But that’s the best they can get if only staying a few days here. But since we signed a lease for 6 months, we were able to get something much more comfortable for our money.
Obviously if one only wants to travel for a year, then traveling slowly as we are would not necessarily be a desirable option since you wouldn’t get a chance to see everything you want - but in our case, we are hell bent on doing this for years, so we don’t feel rushed to pack in as much as possible into a short time frame, and can take the time to chill out in one place for a good long while before moving on.