Pretty dumb idea, have you ever thought about whether someone from outside might possibly nest in Munich for 2 or 3 weeks? Hotel costs should at least balance out. 5AT 500€ hotel costs... As confusing as it sounds, the option to rent a hotel room during the renovation? It certainly isn’t as nice as being at home, but if there was possibly one around the corner and for a limited period that doesn’t span several months. With the amounts mentioned, 2k€ for overnight stays is almost peanuts^^.
Last year I completely redid the bathroom at my parents' place and in the end we spent somewhere around ~6k€ on materials for the toilet, flush-level shower tray, bathtub, tiles around 40€/sqm, fittings on just under 9sqm.
However, with an Ikea base cabinet and mirrored cabinet and a Villeroy & Boch sink for "only" just over 1k€.