Sorry for all the questions – thanks for all the help!

I’m thinking of going to Central/Eastern Europe (Germany, Czech, Poland, Hungary, Slovakia) in June/July/August (maybe September).

I plan to camp some of the time and hostel the main part.

Questions:
a) how cold does it get around this time of year?
b) how warm a sleeping bag should i get, usually the trade off is between warms and heating, eg a -5C is heavier than a 5C
c) do most people use sleeping bags in hostels?
d) is a hood needed/suggested?
e) any other recommendations

Thanks!

Jed

PS my tent wont provide much warmth