We successfully stayed at a relative's home for about 4 days plugged into a 15 amp service and our 5er is 50 amps. The house was an old country farm house and the shed behind the house is were we plugged in. I ran about 150 feet of electric cord to reach the shed. We had no issues. It's all about power management. We never turned on the air conditioners or heat pump. We ran the water heater on propane only. We ran the furnace on propane, and we did not use any electric appliances like coffee pots, toasters, or hair blowers. We did have both televisions operational, electric clocks, and our phones and such plugged in.
At home, we ran our 30 amp TT's on a 15 amp plug from the house for years before installing a 30 amp RV outlet. Now we have a 50 amp, two 30 amp RV outlets, and several 15-20 amp outlets available outside the house and garage.
If you plug into the house, make sure you bring along the 15 amp to 30 amp dogbone or hocky-puck adapter.