WE (2 adults 1 large dog) lived FT in a 34' 5th wheel for 7 yrs traveling.
Roughly 280 sq.ft living space......comfy but !!!!
Our 5th wheel is rated '4 season'......insulation value, heated tanks, high btu furnace/high but A/C Unit.
Expenses were same as for groceries, clothing, MEDICAL, any debt etc.
Insurance was similar as we had a Home Owners Policy on 5th wheel and same coverage on truck
BUT...
we didn't have cost of 5th wheel....no financing
we didn't have cost of truck....no financing
electric costs were similar but propane varied depending on propane usage
(COLD weather...-19*F used a 30# propane cylinder each day. WARM weather propane would go 5-6 weeks and we used it for cooking/fridge/water heater etc)
RV living FT is NOT necessarily cheaper..
Can be less expensive IF current costs are HIGH but one has to really pay attention to costs........and then there is maintenance costs. Things break..even in new rigs.
2 Kid/2 adults..........tight quarters. And can get smaller and smaller each passing day.
Saving up to buy property/build house.
Get cheaper place rent wise and buckle down. At least the kids will stay warm and have some breathing room----you too>
RVng is a great lifestyle....just not basically a cheap one
Good Luck!