the problem with that is if somebody bolts, say, your farm... how long will it take to rebuild a farm from lvl39 to lvl40 with a lvl1 senate? if you can hear the answer without throwing up a little in your mouth then go right ahead and take the senate to lvl1
also, i think there are some buildings that have certain lvl requirements for the senate which you might not be able to rebuild with a lvl1 senate were they to get bolted. so maybe lvl15 or so is a safer option than lvl1